One thing I did is, make a short-cut on your desktop to LaunchIV. Then in the Target. ALl the way in the end. make 1 space, then add these:
-norestrictions -nomemrestrict -noBlockOnLostFocus -forcehighqualitymirrors -noswapdelay
Another thing is to check if you installed any recent mod, which could possibly be the crash trigger.