Guessing this one:
https://portableapps.com/apps/graphics_ ... p_portableMost likely the problem is portableapps Gimp 2.10.8 is a 32 bit application for maximum portability. You need the 32 bit version of
gmic_gimp_qt https://gmic.eu/files/windows/gmic_gimp ... _win32.zip This has not been updated since last December, you get version 2.4.2. Good for most things.
Unzip, put the
whole gmic_gimp_qt folder in the location indicated by Edit -> Preferences -> Folders -> plug-ins
However, assuming my test install is valid, serious issues with this Gimp version.
The Gimp profile is not fully populated. No
...GIMPPortable\Data\.gimp\plug-ins folder. Just make one, it works.
More serious. Python is broken. Check bottom of the Filters menu. There is a Script-Fu entry but no Python-Fu. Quick test with a simple python plugin - nothing.