Reinstall FH completely.
Remove everything from C:\Feralheart
Then install the game again.
Just make sure you backup things you want to keep, and also try the game after the fresh install to see if it works before you slap all your custom things back into it. If your game used to work before though, and you make a CLEAN install, there's not anything that should prevent you from entering the game again since it is exactly the same way as it used to be but also the same game that everyone else has.
