Why are you trying to use the backup copy if the main copy is working?
This problem should not surface at all, let alone re-surface. Are you sure that the latest error you're getting is identical to the first one? Have you been using the "Send Error Report" button?
The error indicates that the game files haven't been saved properly. This should never happen, so I'm not sure why it's happening to you. Is the game on your hard drive, and not on a USB stick or anything like that?