Hello,
I encountered that problem before, a few months ago. I'm not sure if my suggestions will help since that was a long time ago. As Kelsey said, try restarting your game. Did it say anything about troubleshoot? If it did, you might try to open up your troubleshoot if it's a option when the error happens. Try changing your Feral-Heart rendering system into Direct3D9 not OpenGL.
Tell us if it worked for you~