Corrupted .wab file:
p.s. - If your .wab file is located elsewhere, you can easily find it just by searching for .wab. It is probably the only one on your computer. If not, why not also make copies...

My computer crashed in the middle of a defragmentation run, corrupting just about everthing that was running at the time (so, don't have anything else running when you do a defrag!).
After...