Every time I start Killing Floor the game will close when selecting killing floor in the game mode or pressing any button on the keyboard at anytime after leaving the main menu. So far I have tried validating the game cache, each time it saying 1 file did not validate and will be reacquired but no notification of this actually happening and uninstalling and reinstalling the game and validating the cache again (same 1 file not validating not being acquired) , deleting the system folder, deleting the steam client registry blob and refreshing steam. Any ideas?