afrohead said:
How would I know if it's corrupted? I can still see it in the save folder.
Just because it's corrupted doesn't mean the file is gone.
Next time, rely on native in-game saves instead of save states. This is how the N64 is meant to be played anyway.

Also, I think save states and cheats (if you're using them) are known to mess up progress if used excessively, IIRC.