When playing in an online game, everything works great and has worked great for a couple of seasons, but now I am getting a corrupt file message on the team info screen. If I didn't check this then I would never know there was a problem. I have reinstalled the game and I have it on steam. No-one else seems to have this problem. What gives?!?

usually its virus software trying to realtime scan or otherwise locking files during saving or import.

Is the gamefile working for other players in your online game? If so, try adding an exception for the game in your virus software.