Tried searching extensively before posting and couldn't find anything. Maybe I need to get better at searching more thoroughly but I think searching could be optimized to make it easier to catch things like this
I will try again, but someone said that when launching the world the default (single player) host data will overwrite the UUID playerdata file.
If this is true I need to find the default host data file(s) and delete or overwrite before launching the world.
Fabian, I have tried swapping the filenames (UUIDs?) of the two .DAT files within the /playerdata folder - this did not work, should it have? what file would i need to delete?
Is there even a workaround for this? Like if I find the default player data and remove it before loading the world?
Trying to swap host machines for a LAN hosted world. 1.12.2
Can confirm this just happened to me as well; exited singleplayer world, attempted to join back in, I received the error and the world was inaccessible until I closed the game and relaunched.