The Meaning of Life, the Universe, and Everything.
I was playing my singleplayer world when my computer crashed, so I restarted my computer and went into singeplayer, the world I was playing when my computer crashed is no longer there. I check %appdata% in my saves folder and the world is there.
I've tried copy level.dat, level.dat_old, and session.lock all into a newly created minecraft world, still it doesn't show up in the singleplayer world list, I've tried deleting level.dat and renaming level.dat_old to level.dat, but it still does not show up. I've spent a TON of time and work on this world, so please if anyone can help it'd be greatly appreciated!