error: cannot convert 'const __FlashStringHelper*' to 'const char*'

[kelray]

Hi,

Did anybody face this compilation error before?
error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'
Actually it's not just one error, but a series of errors complaining about the "'const __FlashStringHelper*' to 'const char*" type conversion.
I'm using Arduino IDE Windows Store version (1.8.21.0) and NodeMCU32S ESP32 based board.

Cheers.

[mobizt]

You need to update ESP32 Arduino Core SDK to latest version (via Boards Manager).

[kelray]

I did, yet still the problem persists.
Someone suggested this solution for this type conversion error here: espressif/arduino-esp32#1371
But unfortunately it didn't work as well.

[kelray]

Let me post the whole error log, it might be useful for you and anyone interested in solving this issue.
`C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp: In function 'int start_ssl_client(sslclient_context32*, const char*, uint32_t, int, const char*, const char*, const char*, const char*, const char*)':

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:79:66: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: starting socket"));

                                                              ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:90:70: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: opening socket"));

                                                                  ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:99:82: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: could not get ip from host"));

                                                                              ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:110:74: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: connecting to Server..."));

                                                                      ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:124:71: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: server connected"));

                                                                   ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:129:81: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: connect to Server failed!"));

                                                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:140:79: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: begin STARTTLS handshake"));

                                                                           ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:150:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: seeding the random number generator"));

                                                                                  ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:163:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

         strcpy_P(buf, FPSTR("ERROR: "));

                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:174:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: setting up the SSL/TLS structure..."));

                                                                                  ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:187:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

         strcpy_P(buf, FPSTR("ERROR: "));

                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:202:70: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: loading CA cert"));

                                                                  ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:215:47: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:227:69: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: setting up PSK"));

                                                                 ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:233:100: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: pre-shared key not valid hex or too long"));

                                                                                                ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:264:73: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: set mbedtls config"));

                                                                     ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:273:47: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:297:71: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: loading CRT cert"));

                                                                   ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:308:47: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:318:74: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: loading private key"));

                                                                      ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:332:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: setting hostname for TLS session..."));

                                                                                  ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:343:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

         strcpy_P(buf, FPSTR("ERROR: "));

                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:360:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

         strcpy_P(buf, FPSTR("ERROR: "));

                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:373:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: performing the SSL/TLS handshake..."));

                                                                                  ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:385:47: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:413:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: verifying peer X.509 certificate..."));

                                                                                  ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:422:90: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: failed to verify peer certificate!"));

                                                                                      ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:430:75: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: certificate verified"));

                                                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp: In function 'void stop_ssl_socket(sslclient_context32*, const char*, const char*, const char*)':

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:457:74: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: cleaning SSL connection"));

                                                                      ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp: In function 'int data_to_read(sslclient_context32*)':

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:486:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

         strcpy_P(buf, FPSTR("ERROR: "));

                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp: In function 'bool verify_ssl_fingerprint(sslclient_context32*, const char*, const char*)':

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:597:81: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: fingerprint too short"));

                                                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:605:80: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: invalid hex sequence"));

                                                                            ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:619:88: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: could not fetch peer certificate"));

                                                                                    ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:636:81: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: fingerprint doesn't match"));

                                                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp: In function 'int starttlsHandshake(sslclient_context32*, int)':

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:726:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: waiting incoming data failed!"));

                                                                                 ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:736:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: reading incoming data failed!"));

                                                                                 ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:749:46: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

     strcpy_P(hMsg, FPSTR("EHLO DUDE\r\n"));

                                          ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:751:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: send SMTP command extended HELO"));

                                                                                  ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:757:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: send SMTP command failed!"));

                                                                                 ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:766:89: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: waiting incoming data failed!"));

                                                                                     ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:776:89: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: reading incoming data failed!"));

                                                                                     ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:787:41: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

 strcpy_P(hMsg, FPSTR("STARTTLS\r\n"));

                                     ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:789:81: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

     ssl_client->_debugCallback(FPSTR("INFO: send STARTTLS protocol command"));

                                                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:795:94: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: send STARTTLS protocol command failed!"));

                                                                                          ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:804:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: waiting incoming data failed!"));

                                                                                 ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ssl_client32.cpp:814:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("ERROR: reading incoming data failed!"));

                                                                                 ^

Multiple libraries were found for "WiFi.h"
Used: C:\Users\xxxx\Documents\ArduinoData\packages\esp32\hardware\esp32\1.0.3\libraries\WiFi
Not used: C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.21.0_x86__mdqgnx93n4wtt\libraries\WiFi
Multiple libraries were found for "ESP32_MailClient.h"
Used: C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client
Not used: C:\Users\xxxx\Documents\Arduino\libraries\arduino_98700
Multiple libraries were found for "SD.h"
Used: C:\Users\xxxx\Documents\ArduinoData\packages\esp32\hardware\esp32\1.0.3\libraries\SD
Not used: C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.21.0_x86__mdqgnx93n4wtt\libraries\SD
C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp: In member function 'bool ESP32_MailClient::readMail(IMAPData&)':

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:90:63: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: connecting to IMAP server..."));

                                                           ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:125:67: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

   ESP32MailDebug(FPSTR("ERROR: could not connect to internet"));

                                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:164:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

     ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:191:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: server connected"));

                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:214:58: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: send imap command LOGIN"));

                                                      ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:233:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:255:59: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

   ESP32MailDebug(FPSTR("INFO: send imap command LIST"));

                                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:270:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

     ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:299:60: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: send imap command EXAMINE"));

                                                        ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:316:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:383:53: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: search message"));

                                                 ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:437:53: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:512:50: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

   ESP32MailDebug(FPSTR("INFO: fetch message"));

                                              ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:585:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

     ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:765:59: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

             ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:806:65: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

                   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:861:59: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: send imap command LOGOUT"));

                                                       ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:881:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:896:58: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: message fetch completed"));

                                                      ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp: In member function 'bool ESP32_MailClient::sendMail(SMTPData&)':

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1013:63: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: connecting to SMTP server..."));

                                                           ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1047:67: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

   ESP32MailDebug(FPSTR("ERROR: could not connect to internet"));

                                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1074:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1081:56: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: smtp server connected"));

                                                    ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1107:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

     ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1122:57: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: send smtp HELO command"));

                                                     ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1137:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1151:63: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: send smtp AUTH LOGIN command"));

                                                           ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1166:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1179:68: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: log in with username and password"));

                                                                ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1194:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1213:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1227:52: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: send email header"));

                                                ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1282:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1327:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

     ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1373:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

     ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1400:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

     ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                               ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1415:50: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: send email body"));

                                              ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1430:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1463:55: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

   ESP32MailDebug(FPSTR("INFO: send attachment..."));

                                                   ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1531:46: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: finalize..."));

                                          ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1556:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

   ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                             ^

C:\Users\xxxx\Documents\Arduino\libraries\ESP32_Mail_Client\src\ESP32_MailClient.cpp:1570:58: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

 ESP32MailDebug(FPSTR("INFO: email sent successfully"));

                                                      ^

exit status 1
Error compiling for board Node32s.`

[mobizt]

Ok I just khow this issu with lates sdk version.
I will remove the use of this macro in the next update.
You can go back to v 1.0.2 at this time.

[kelray]

Still the problem isn't resolved even after reverting to v1.0.2., it looks like something from my end that either needs to be updated or removed. I will keep digging. Thanks anyways for the help.

[mobizt]

Strange issue, there is no error about this in my test with 1.0.2

[grobekelle]

I´m facing exactly the same issue.

[mobizt]

Strange, set debug to false until update.

[grobekelle]

Just want to let you know, that switching back to esp32 1.0.2 solved the issue on my site.

[BIueMan]

i have the same problem. just chagne esp32 to 1.0.2 and with no diffrents :/

Arduino: 1.8.10 (Windows 10), Board: "ESP32 Dev Module, Disabled, Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS), 160MHz (WiFi/BT), QIO, 80MHz, 4MB (32Mb), 921600, None"

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp: In member function 'bool ESP32_MailClient::readMail(IMAPData&)':

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:90:63: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: connecting to IMAP server..."));

                                                               ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:125:67: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

       ESP32MailDebug(FPSTR("ERROR: could not connect to internet"));

                                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:164:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

         ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:191:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: server connected"));

                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:214:58: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: send imap command LOGIN"));

                                                          ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:233:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:255:59: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

       ESP32MailDebug(FPSTR("INFO: send imap command LIST"));

                                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:270:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

         ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:299:60: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: send imap command EXAMINE"));

                                                            ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:316:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:383:53: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

         ESP32MailDebug(FPSTR("INFO: search message"));

                                                     ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:437:53: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

           ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                     ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:512:50: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

       ESP32MailDebug(FPSTR("INFO: fetch message"));

                                                  ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:585:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

         ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:765:59: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

                 ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:806:65: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

                       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:861:59: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: send imap command LOGOUT"));

                                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:881:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:896:58: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: message fetch completed"));

                                                          ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp: In member function 'bool ESP32_MailClient::sendMail(SMTPData&)':

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1013:63: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: connecting to SMTP server..."));

                                                               ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1047:67: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

       ESP32MailDebug(FPSTR("ERROR: could not connect to internet"));

                                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1074:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1081:56: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: smtp server connected"));

                                                        ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1107:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

         ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1122:57: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: send smtp HELO command"));

                                                         ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1137:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1151:63: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: send smtp AUTH LOGIN command"));

                                                               ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1166:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1179:68: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: log in with username and password"));

                                                                    ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1194:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1213:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1227:52: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: send email header"));

                                                    ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1282:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1327:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

         ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1373:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

         ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1400:51: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

         ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                   ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1415:50: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: send email body"));

                                                  ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1430:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1463:55: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

       ESP32MailDebug(FPSTR("INFO: send attachment..."));

                                                       ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1531:46: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: finalize..."));

                                              ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1556:49: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebugLine(const char*, bool)'

       ESP32MailDebugLine(FPSTR("ERROR: "), false);

                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ESP32_MailClient.cpp:1570:58: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '1' to 'void ESP32MailDebug(const char*)'

     ESP32MailDebug(FPSTR("INFO: email sent successfully"));

                                                          ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp: In function 'int start_ssl_client(sslclient_context32*, const char*, uint32_t, int, const char*, const char*, const char*, const char*, const char*)':

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:79:66: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: starting socket"));

                                                                  ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:90:70: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: opening socket"));

                                                                      ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:99:82: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: could not get ip from host"));

                                                                                  ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:110:74: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: connecting to Server..."));

                                                                          ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:124:71: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: server connected"));

                                                                       ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:129:81: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: connect to Server failed!"));

                                                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:140:79: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: begin STARTTLS handshake"));

                                                                               ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:150:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: seeding the random number generator"));

                                                                                      ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:163:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:174:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: setting up the SSL/TLS structure..."));

                                                                                      ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:187:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:202:70: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: loading CA cert"));

                                                                      ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:215:47: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

                 strcpy_P(buf, FPSTR("ERROR: "));

                                               ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:227:69: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: setting up PSK"));

                                                                     ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:233:100: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

                 ssl_client->_debugCallback(FPSTR("ERROR: pre-shared key not valid hex or too long"));

                                                                                                    ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:264:73: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: set mbedtls config"));

                                                                         ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:273:47: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

                 strcpy_P(buf, FPSTR("ERROR: "));

                                               ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:297:71: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: loading CRT cert"));

                                                                       ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:308:47: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

                 strcpy_P(buf, FPSTR("ERROR: "));

                                               ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:318:74: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: loading private key"));

                                                                          ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:332:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: setting hostname for TLS session..."));

                                                                                      ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:343:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:360:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:373:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: performing the SSL/TLS handshake..."));

                                                                                      ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:385:47: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

                 strcpy_P(buf, FPSTR("ERROR: "));

                                               ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:413:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: verifying peer X.509 certificate..."));

                                                                                      ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:422:90: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: failed to verify peer certificate!"));

                                                                                          ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:430:75: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: certificate verified"));

                                                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp: In function 'void stop_ssl_socket(sslclient_context32*, const char*, const char*, const char*)':

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:457:74: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: cleaning SSL connection"));

                                                                          ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp: In function 'int data_to_read(sslclient_context32*)':

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:486:43: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

             strcpy_P(buf, FPSTR("ERROR: "));

                                           ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp: In function 'bool verify_ssl_fingerprint(sslclient_context32*, const char*, const char*)':

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:597:81: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

                 ssl_client->_debugCallback(FPSTR("ERROR: fingerprint too short"));

                                                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:605:80: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

                 ssl_client->_debugCallback(FPSTR("ERROR: invalid hex sequence"));

                                                                                ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:619:88: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: could not fetch peer certificate"));

                                                                                        ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:636:81: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: fingerprint doesn't match"));

                                                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp: In function 'int starttlsHandshake(sslclient_context32*, int)':

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:726:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: waiting incoming data failed!"));

                                                                                     ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:736:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: reading incoming data failed!"));

                                                                                     ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:749:46: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

         strcpy_P(hMsg, FPSTR("EHLO DUDE\r\n"));

                                              ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:751:86: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("INFO: send SMTP command extended HELO"));

                                                                                      ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:757:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

                 ssl_client->_debugCallback(FPSTR("ERROR: send SMTP command failed!"));

                                                                                     ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:766:89: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

                 ssl_client->_debugCallback(FPSTR("ERROR: waiting incoming data failed!"));

                                                                                         ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:776:89: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

                 ssl_client->_debugCallback(FPSTR("ERROR: reading incoming data failed!"));

                                                                                         ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:787:41: error: cannot convert 'const __FlashStringHelper*' to 'const char*' for argument '2' to 'char* strcpy(char*, const char*)'

     strcpy_P(hMsg, FPSTR("STARTTLS\r\n"));

                                         ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:789:81: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

         ssl_client->_debugCallback(FPSTR("INFO: send STARTTLS protocol command"));

                                                                                 ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:795:94: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: send STARTTLS protocol command failed!"));

                                                                                              ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:804:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: waiting incoming data failed!"));

                                                                                     ^

C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master\src\ssl_client32.cpp:814:85: error: cannot convert 'const __FlashStringHelper*' to 'const char*' in argument passing

             ssl_client->_debugCallback(FPSTR("ERROR: reading incoming data failed!"));

                                                                                     ^

Multiple libraries were found for "SPI.h"
 Used: C:\Users\UserPC\Documents\Arduino\hardware\espressif\esp32\libraries\SPI
Multiple libraries were found for "SPIFFS.h"
 Used: C:\Users\UserPC\Documents\Arduino\hardware\espressif\esp32\libraries\SPIFFS
Multiple libraries were found for "HTTPClient.h"
 Used: C:\Users\UserPC\Documents\Arduino\hardware\espressif\esp32\libraries\HTTPClient
Multiple libraries were found for "WiFiClientSecure.h"
 Used: C:\Users\UserPC\Documents\Arduino\hardware\espressif\esp32\libraries\WiFiClientSecure
Multiple libraries were found for "ESP32_MailClient.h"
 Used: C:\Users\UserPC\Documents\Arduino\libraries\ESP32-Mail-Client-master
 Not used: C:\Users\UserPC\Documents\Arduino\libraries\arduino_655856
Multiple libraries were found for "WiFi.h"
 Used: C:\Users\UserPC\Documents\Arduino\hardware\espressif\esp32\libraries\WiFi
 Not used: C:\Program
Multiple libraries were found for "SD.h"
 Used: C:\Users\UserPC\Documents\Arduino\hardware\espressif\esp32\libraries\SD
 Not used: C:\Program
 Not used: C:\Users\UserPC\Documents\Arduino\libraries\SD
Multiple libraries were found for "FS.h"
 Used: C:\Users\UserPC\Documents\Arduino\hardware\espressif\esp32\libraries\FS
exit status 1
Error compiling for board ESP32 Dev Module.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

[mobizt]

Thank everyone, I will remove the incompatible macro from the library in next update soon.

[asclanac]

Hi: You can add me to the list of folks getting these errors. All was going really well in my recent ascent of the learning curve and I had ESP32-Mail-Client working perfectly in a simple sketch sending regular emails containing temperature and humidity, etc. Big change happened when I accepted upgrades yesterday for Arduino. Trying to roll back versions has been unsuccessful so far, as I do not know what versions I had before the update. If anyone can confirm which versions of Arduino (currently 1.8.9), esp32 (currently 1.0.3) and ESP32-Mail-Client actually work, please let us know.

[mobizt]

@asclanac, please try esp32 v1.0.2.

[asclanac]

Thanks. Now rolled back esp32 board version to 1.0.2 and it compiles successfully.

…

On Mon, Sep 23, 2019 at 6:02 PM mobizt ***@***.***> wrote: @asclanac <https://github.com/asclanac>, please try esp32 v1.0.2. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#25?email_source=notifications&email_token=ANJDPD6ZJRJLELKOPCDJ763QLFKI3A5CNFSM4IY5P5PKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD7MT5HY#issuecomment-534331039>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ANJDPD37UFR5JSA2LNU5MQTQLFKI3ANCNFSM4IY5P5PA> .

[Bolukan]

See #26 for 1.0.3