So I was playing this on my favorite map Excess Island Night. Now I would say that this happened randomly while I was playing, but something obviously happened here. I was just running around shooting dudes and this error[imgur.com] appeared.

From what I can tell from the error message, it had something to do with me standing on the corpse of a Combine. It also crashed me to my desktop, and I mean the game instantaneously just closed and this popup appeared. I had not changed anything from the game. In fact, I just updated it and decided to play it some (BTW, the helicopter AI works again). Some help would be appreciated.