@Vanished, Shallow's suggestion should work for you- when you uninstall, make sure all traces of FeralHeart (there will be old files leftover) are deleted.
This way, your computer can start over fresh when you reinstall.
Also, have you exported any maps recently?
It could be that your particles are acting up. Just for the heck of it, you could also check FeralHeart >> Media >> Particles, and delete any files that end in _0 or _1.
Good luck, floof.