Hang on, before you reinstall-
Have you exported any maps recently? If so, check your FeralHeart folder >> Media >> Particles, and delete anything that that ends in _0 or _1.
But, if you haven't exported any maps, then it likely is a corrupted file. As EnderStar said, an uninstall/reinstall would then be your best bet.
Edit: Derp. Or what BouncyLion said. (Sorry about that!)