It does sound like something was corrupted. I'm not sure if it's one of the files in the game itself, or one of your saves, though. Try redownloading the game. You can try to move your save folder to the nee download. If you get the same error after moving your save folder to the new download, then it's likely that one or more of the files in the save folder were corrupted. If the problem is with the saves, then try deleting/removing the save folder, and playing a new game. Let me know if you still get the error if you start a new game on a fresh install with no previous saves in the game's folders.