Now the mission has started crashing on me.
It's hard to describe, but it's happened 5-6 times in a row now. The first time I went to put in the cheats as soon as the mission starts, and when I ~+w to get infinite missles (I had zero) the game hangs for 2-3 seconds then crashes. Another time it crashed when a message tried to play, and another time when I tried to look behind.
Every time it's less than 15 seconds into the mission, and its a proper crash ("xxx encountered a problem and needs to close. Please tell Microsoft about this problem* *we love invading your privacy and meddling with computer software that we aren't affiliated with or have any clue about whatsoever
"), not an assertion fault.