I came back to my PC and it had crashed: caps lock was frozen and the mouse or keyboard had no effect on the screen which was black. After restarting, I tried to enter my world which I have spent multiple months on and it crashed at once. It affected that world only. The copy version I proceeded to make went down as well. Each time I was kicked out of minecraft. I have lost all of my hard work. It affected 1.15 but it says there are no matches.
MCPE-60246
losing saved worlds after PC crash
Resolved
Invalid
0
It sounds like you had a system crash, not a bug issue.
Although the game tries to minimize world losses by auto-saving and repairing damaged worlds when you open them, sometimes it just isn't possible to recover a world after a system crash. This is one reason the Windows 10 version gives you the Export button to allow you to make backups.