Workaround
Try replacing level.dat by level.dat_old in your world folder.
The bug
Worlds can be deleted by using the following steps. However, they remain in the ''saves'' folder.
How to reproduce
Create a world with some specific name (to make sure that you won't think that is other world)
Load it
Shut down the computer by pushing the button that you switch on your computer (pull at least 5 seconds)
Switch the computer on again
Open Minecraft
Open the world folder
→ ❌ Notice that the world is goneGo to the ''saves'' folder
→ ✔ Notice that the save is still there
Related issues
is duplicated by
MC-170433
My World has disappeared
MC-175270
World gets deleted when restarting
MC-177433
world disappeared help
MC-177766
Lost my world
MC-185092
World lost.
MC-199894
when I entered minecraft my world was gone
MC-200360
World deletion
MC-200367
World deletion
MC-216728
my Minecraft long lasting world randomly got deleted
MC-219718
I have lost my world out of nothing I had a world called GUYS
relates to
Comments
migrated
violine1101
This probably happens when the level.dat file is saved while the computer is shutdown, causing it to be corrupted. When you create a new world then, it'll probably just overwrite the level.dat file.
Can you check whether removing the level.dat file and replacing it with a copy of the level.dat_old file makes the world visible again?
migrated
Thank you sooo much. IT WORKED!!!
wobst.michael
Actually a duplicate of MC-115237, but leaving it open since it's quite detailed and a Mojang Priority has been assigned.
migrated
hi, same problem, need to rename the file level.dat_old, or it works by just coping it? (means that i will have 2 level.dat_old? and it will have all my building? or just will be playable again but with everything gone?
You can actually revert this by creating a new world, but you have to create it using the exact same name the original world's save folder has.