Difficult to say what is wrong. Sometimes installing / re-installing / trying other versions can make things worse.
Just out is the latest stable gmic_gimp_qt 2.82 I would get this and use the gmic installer which correctly installs all the files. Get rid of what you already have first.
https://gmic.eu/files/windows/gmic_2.8.2..._win64.exe
The installation should look like this https://www.gimpusers.com/system/attachm...1578913675
Other than that, try deleting the gmic profile C:\Users\"yourname"\AppData\Roaming\gmic sometimes remains of old data can cause problems.
Refreshing the filters will create a new one.
Other wise, if you can post a screenshot of the whole Gimp + gmic interface it might give a clue.
Just out is the latest stable gmic_gimp_qt 2.82 I would get this and use the gmic installer which correctly installs all the files. Get rid of what you already have first.
https://gmic.eu/files/windows/gmic_2.8.2..._win64.exe
The installation should look like this https://www.gimpusers.com/system/attachm...1578913675
Other than that, try deleting the gmic profile C:\Users\"yourname"\AppData\Roaming\gmic sometimes remains of old data can cause problems.
Refreshing the filters will create a new one.
Other wise, if you can post a screenshot of the whole Gimp + gmic interface it might give a clue.