I had left my laptop while I went to do a chore which took me off track. When I cam back my laptop was glitched out. It wouldnt let me log on and then minecraft was stuck as the opening screen rather than on my world. I had no choice but to restart my laptop because it was lagging so bad. Once restarted my world had simply vanished. All my other worlds were intact but they're useless considering I havent used them or use them actively for months. I put all my time into that one world and when I came back poof. I have no storage of it, no nothing of it.