I opened the LAN world and enabled cheating. then I switched to spectator mode.
I found a zombie spawner close to x=70.11, y=23.68, z=208.51, i tried to get back to the home close to the spawn. then crashed.
after crash, I tried to optimize the world in the "edit" button and join the world. it didn't crash but it shows nothing except the blue sky.
Please do not mark unreleased versions as affected.
You don't have access to them yet.