Hmm the "FeralHeart.exe has stopped working" problem is usually because of some file problem I believe but if you're saying you can get into Fluorite on your other account with out the crash then it can't be that though

. Are you sure it's not the usually crashes out of Fluorite because there are too many people there right now and maybe you are just getting lucky squeezing in on your other account? Just in case did you check your particles for doubles? Any files in your particles ending in _0, _1, _2 etc delete them. Also try running the program as an admin or you could also try changing you're rendering subsystem by clicking options in the game and then video settings and switch it to either OpenGL or Direct3D9.