Have you installed any items, markings, or add-ons lately? If you have, it's quite possible that you have misplaced or accidentally removed a file. You could also try checking for double particles located in your Feral Heart >> media >> particles folder (delete any files ending in _0, _1, etc.,) and make sure that you have downloaded the new patch. If all else fails, you can always delete your FH folder (while backing up any files that you want to keep, such as maps, presets, and screenshots) and try for a fresh re-installation of the game.