I set the game to peaceful, and was just hoping around a nether fort, down to the last chest and... the the game starts lagging out, dropping from 60 fps to 1fps.
the whole logout and go back in didn't work cause as soon as the game unlagged I had already respawned.
and then the thing CTD'ed.
about 2/3 of the stuff isn't replaceable (what I can remember) and the last backup of the map is from 2019, windows didn't bother to keep an over version ether.
I already tried to use NBT but that stupid tool keeps crashing as well.