It was a random type of crash, but I did notice every time I tried to fly the P51D in any mission editor flight would crash, usually right after the start of the mission. All drivers are up to date, no programs, other than TIR5 is running. I did have an update issue last month with the major security update issued by Microsoft. I did a restore and I thought things were all right but snice I posted the original post in this thread I decided to take my computer into my computer provider because of other windows issues so maybe that Windows problem maybe the problem.. When I get it back I will post if they found an issue...