it's probably missing the level.dat and level.dat_old files - if so, there's no real way to completely repair them without a world backup. Now, if you DO have a world backup, you need to copy the level.dat from it to the world folder and then IMPORTANT delete the player data from it using NBTExplorer. If you DON'T have a world backup, you can copy the level.dat from another world (you still want to delete the player data though), but you will get chunk errors when generating new chunks because the seed will be different.
And if you're using mods, the modded blocks and items will probably get messed up.
When I try to play a map, it's missing from my list of maps. If I go into my saves, the map(s) are there but don't show up in the section in game.
Try repairing them with mcedit.
How do I use mcedit on a map that doesn't show up in my list of maps?
it's probably missing the level.dat and level.dat_old files - if so, there's no real way to completely repair them without a world backup. Now, if you DO have a world backup, you need to copy the level.dat from it to the world folder and then IMPORTANT delete the player data from it using NBTExplorer. If you DON'T have a world backup, you can copy the level.dat from another world (you still want to delete the player data though), but you will get chunk errors when generating new chunks because the seed will be different.
And if you're using mods, the modded blocks and items will probably get messed up.
Creator of Metroid Cubed 3, a Metroid-themed mod! Become a donator today!