Every time I load any of my last three save files (regular, quick, and auto), the program immediately crashes. What can I do to troubleshoot? If I load an older file, there isn't any issue (except that I'm losing about 50hrs of game play progress ).

Any ideas?

Oblivion has some issues with overwriting saves. Be they quick, auto, or, regular saves. If you overwrite the files on a regular basis, you will have trouble. At this point, there is no tool to fix save games broken by being overwritten too many times. (and 'just once' can be 'too many'.....)

Turn off all autosave options.

Don't use quicksaves at all.....

Don't overwrite your hard saves.

End of problems. Of course, that doesn't get you back your 50 hours of game play...... Ooops.

But it would corrupt all three of my last saves at the same time? All three were fine yesterday! ....great sadness.

Depends. did you overwrite the last one that loaded without trouble? Did you save over it after that? Did you use auto or quicksave in there as well?