If you removed the game completely and reinstalled this shouldn't stay there.
If you got this error after adding custom things to the game it should work just fine if you reinstall it COMPLETELY.
Thing is, that if you're making maps that you want to keep, you MUST make backups of the maps, and ALL the files the map is using. Otherwise the map might crash when you try to open them up next time. Just make sure you don't copy the meshes that caused the problem the first time. Cause if you install a new game again that's working, and then paste the meshes that caused this issue in the first place. Ofcourse it wont work!
So you need to make a backup on all the things you know these maps use, then uninstall the game. Open up your computers C:\ driver, and remove the WHOLE FeralHeart folder there, removing everything.
Next time you install the game it should work just fine. But if you don't install all the files for your map correctly it might not work either.
Be careful so you get all the files needed for the maps you made.