I've taken a look at your world.dat file, Larry, and even without knowing much about the structure of the file, I can tell that it's corrupted. It cuts off the data about halfway through and fills in the rest with empty bytes. And since this file keeps track of league data as your league progresses, it's not as easy as replacing it with a world.dat file from another league, I'm afraid. Unless you've got a league backup or can revert to a System Restore point, you may be out of luck.
Hopefully one of the higher-ups can prove me wrong...