diff --git a/src/core/src/bootstrap/EnvLayer.py b/src/core/src/bootstrap/EnvLayer.py
index 79b1803c..5bb598c7 100644
--- a/src/core/src/bootstrap/EnvLayer.py
+++ b/src/core/src/bootstrap/EnvLayer.py
@@ -135,8 +135,9 @@ def get_env_var(self, var_name, raise_if_not_success=False):
             print("Error occurred while getting environment variable [Variable={0}][Exception={1}]".format(str(var_name), repr(error)))
             if raise_if_not_success:
                 raise
+            return None
 
-    def run_command_output(self, cmd, no_output, chk_err=True):
+    def run_command_output(self, cmd, no_output=False, chk_err=True):
         # type: (str, bool, bool) -> (int, any)
         """ Wrapper for subprocess.check_output. Execute 'cmd'. Returns return code and STDOUT, trapping expected exceptions. Reports exceptions to Error if chk_err parameter is True """
 
@@ -185,7 +186,7 @@ def __str__(self):
             output = subprocess.check_output(no_output, cmd, stderr=subprocess.STDOUT, shell=True)
         except subprocess.CalledProcessError as e:
             if chk_err:
-                print("Error: CalledProcessError. [Code={0}][Command={1}][Result={2}]".format(str(e.returncode), e.cmd, self.__convert_process_output_to_ascii(e.output[:-1])), file=sys.stdout)
+                print("Error: CalledProcessError. [Code={0}][Command={1}][Result={2}]".format(str(e.return_code), e.cmd, self.__convert_process_output_to_ascii(e.output[:-1])), file=sys.stdout)
             if no_output:
                 return e.return_code, None
             else:
diff --git a/src/extension/src/EnvLayer.py b/src/extension/src/EnvLayer.py
index e4db7d3c..d83410a0 100644
--- a/src/extension/src/EnvLayer.py
+++ b/src/extension/src/EnvLayer.py
@@ -97,7 +97,7 @@ def __str__(self):
                 no_output, cmd, stderr=subprocess.STDOUT, shell=True)
         except subprocess.CalledProcessError as e:
             if chk_err:
-                print("Error: CalledProcessError.  Error Code is: " + str(e.returncode), file=sys.stdout)
+                print("Error: CalledProcessError.  Error Code is: " + str(e.return_code), file=sys.stdout)
                 print("Error: CalledProcessError.  Command string was: " + e.cmd, file=sys.stdout)
                 print("Error: CalledProcessError.  Command result was: " + self.__convert_process_output_to_ascii(e.output[:-1]), file=sys.stdout)
             if no_output: