Okay, try this. It's helped me before.
- Go into your C:\FeralHeart\media\particles folder. Inside of it, there should be particles with the name _01 _02 in them. These are copies of an already existing particle. Remove these from the folder and then run the game.
- Remove the maps in your "exports folder" then try to run the game again.
- if that fails open your ogre.cfg with notepad and change your rendering mode to the one NOT selected.