As said previously, this need a server restart to be fixed. It already happened with me four times in one week, and there is nothing we can do but wait for the server restart. And since it's weekend, that might only happen on monday. But FH isn't your life. There are other games you can play or other things to do.
Hawkwing, have you tried to reinstall FeralHeart? Or, have you download any maps or different meshes before it started to crash? You're having a different sort of problem, that's not related to the server, I suppose. Also, go to FeralHeart > Media > Particles and search if there are any files there that ends with '_0' or other numbers and delete them.