[🐛 Bug]: Selenium SessionNotCreatedException: "User data directory is already in use"

[ammarft-ai]

What happened?

I am trying to launch a headless Chrome WebDriver using Selenium in Python. However, I keep encountering this error:

How can we reproduce the issue?

from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from webdriver_manager.chrome import ChromeDriverManager

def createModel():
    service = Service(ChromeDriverManager().install())
    options = webdriver.ChromeOptions()
    
    # Specifying user data directory
    options.add_argument("--user-data-dir=/root/video-downloader/tmp/selenium-user-data")  
    options.add_argument("--headless=new")
    options.add_argument("--start-maximized")

    driver = webdriver.Chrome(service=service, options=options)
    return driver

driver = createModel()
driver.get("https://www.google.com")
print(driver.title)
driver.quit()

Relevant log output

selenium.common.exceptions.SessionNotCreatedException: Message: session not created: probably user data directory is already in use, 
please specify a unique value for --user-data-dir argument, or don't use --user-data-dir

Operating System

Ubuntu

Selenium version

4.29.0

What are the browser(s) and version(s) where you see this issue?

Chrome

What are the browser driver(s) and version(s) where you see this issue?

Google Chrome 133.0.6943.126 ChromeDriver stable(auto)

Are you using Selenium Grid?

No response

[github-actions]

@ammarft-ai, thank you for creating this issue. We will troubleshoot it as soon as we can.

---

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Thank you!

[diemol]

I am not sure how we can help. You need to make sure the profile is not being used.

[cgoldberg]

This could be caused by trying to access a profile that's already in use, or if the profile is not readable/writeable (yours seems to be owned by root?)

Either way, the error message is coming from chromedriver, so I don't think there is anything to fix from the selenium side.

[kiyotsu]

It also occurs in my environment.
I am running my tool with administrator privileges.
This error does not occur except when running as administrator.
I assume that an Edge version update triggers this error.

OS:Windows10
language:c#

[thepbnk]

It also occurs in my environment. I am running my tool with administrator privileges. This error does not occur except when running as administrator. I assume that an Edge version update triggers this error.

OS:Windows10 language:c#

I don't know the cause, but I avoided the error by running msedgedriver.exe before initializing the driver.

• Environment where it occurred

• OS: Windows 10
• c# Selenium Webdriver 4.2.0
• msedge: 133.0.6943.127

static void Main()
        {
            string exePath = System.Reflection.Assembly.GetExecutingAssembly().Location;
            string exeDirectory = Path.GetDirectoryName(exePath);
            String GetDrivePath = exeDirectory;
            String driverFileName = "msedgedriver.exe";


            EdgeDriverService eds = EdgeDriverService.CreateDefaultService(GetDrivePath, driverFileName);
            eds.HideCommandPromptWindow = true;
            eds.SuppressInitialDiagnosticInformation = true;

            StartProcessAsStandardUser(GetDrivePath + "\\" + driverFileName, eds.Port);

            System.Threading.Thread.Sleep(1000);
            EdgeOptions options = GetBrowserOption;
            string navigateUrl = "https://www.google.com";
            using (var driver = new EdgeDriver(eds, options))
            {
                driver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(2);
                driver.Navigate().GoToUrl("about:blank");
                driver.Navigate().GoToUrl(navigateUrl);
            }
        }

public static void StartProcessAsStandardUser(string fileName, int port)
        {

            ProcessStartInfo psi = new ProcessStartInfo
            {
                FileName = "runas.exe",
                Arguments = $"/trustlevel:0x20000 \"{fileName} --port={port}\"",
                UseShellExecute = true,
                CreateNoWindow = true,
                WindowStyle = ProcessWindowStyle.Hidden
            };

            try
            {
                psi.WorkingDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Windows);
                var proc = Process.Start(psi);
            }
            catch (Exception ex)
            {

            }
        }

[cgoldberg]

Try running chromdriver.exe from the command line, passing it the --user-data-dir argument and supplying the location of your profile. That will verify this is an issue with ChromeDriver and not selenium.

However, since the error is coming from ChromeDriver... this doesn't look like a selenium issue and it should reported to the ChromeDriver devs.

[cgoldberg]

@thepbnk

Why are you running as Admin?

Also, the reported issue was for Chrome, not Edge.

[thepbnk]

@cgoldberg
Running it with administrator rights was a method I found while looking for a way to reproduce the error.

The PC where the error occurred did not have administrator rights, but it did occur. And I was able to avoid the error with this method.

Although it is a Chrome issue, I thought that a similar method could be used, so I left a comment.

[VietND96]

I am running my tool with administrator privileges.
This error does not occur except when running as administrator.

If running as admin (in Windows) or with sudo (in Linux), can you try to pass browser arg --no-sandbox to see any help?
Refer to https://stackoverflow.com/a/70385974/14532601, #14609 (comment)