VERY IMPORTANT, GAMEBREAKING MAP WIPE GLITCH
I was able to recreate a glitch where your map will completely wipe all structures and entities, leaving nothing but barren landscape.
If you Alt-F4 your game while in the process of logging out of the world, it will wipe the map.
I happened to do this by accident and my world that me and my 3 friends were working on for about a week just got wiped. Probably 150+ hours of work gone. This is a horrible glitch and pretty depressing, please fix.