Hi,

I havent runned Multimc since the last update. so i havent touched my save since over 1 month almost.

When i start my game it says Minecraft backup level dat being used, and that im adviced to create a backup save.
So i do. When entering my world, everything is corrupt.

Im at 1.12.2 Forge 14.23.4.2705 i have mods installed, and everything worked fine for a year now.
Ive tried latest update for 1.12.2 and ive just tried Pam's+HarvestCraft+1.12.2L just for a random test.
Whenever i try to load a world i get to the level.dat being used issue.

When i remove your mod, its all working.

I have no error messages, since ive closed the console window before the level dat message appeared.

I have tried creating a new world, same instance, and copied the new level.dat file over the old.
This had no effect. I also have a backup of my world, and when i try it, i get the same message about level dat being used.