I do a a lot of alt tabbing as well, and I get the exact same problem with the screen going pretty much completely extremely high contrast white. Although I can't seem to get rid of it now, and it feels like I'm being forced to redo the mission only to keep experiencing the bug and the several other ones I'm getting as well. I'd suggest this company pay for actual programmers so they can put out real games, not this trashy bargain bin shit.