TestExternalFiles.py fails unless run from cmd prompt window

[Stumpy842]

If I run TestExternalFiles.py by double-clicking from File Explorer it fails with the error:
ERROR: Cannot create the report file as specified: Report.txt

where I have set the report name in the RM-Python-config.ini file to 'Report.txt'

However the script works properly if I launch it from an open Command Prompt window. It's not a huge deal but is definitely not expected behavior.