maybe try to start GIMP from terminal* with --verbose
then run your script, maybe you will have more details in the terminal
in all case
is your friend in the terminal to know what you can pass
EDIT
* I just saw you're on Microsoft's Windows, commands above are for Linux/MacOS, you might need to adapt those command for your OS
Code:
gimp --verbose
in all case
Code:
man gimp
EDIT
* I just saw you're on Microsoft's Windows, commands above are for Linux/MacOS, you might need to adapt those command for your OS