Is it p6? cause if so its a known bug...not known by the makers but known by users lol....its happened to me....only suggestion i can say is....save several copies of the same files in diff folders...cause if you have 3 copies of all the same file even with diff names in one folder it corrupts them all....its a p.i.t.a .......and very frustrating when you havent saved it for a while lol

"I didn't lose my mind, it was mine to give away"