My friends and I were playing on our own server last night and my computer, which is running the server, ran out of battery. When I started it back up, all I did was try and turn the server on and I got this error.
[SEVERE] Unexpected exception
What do I do? I tried starting a new map and it worked fine. We've been working on it for weeks and its at around 66 MB, so we really don't want to lose it. Is it possible the file is corrupted? I hope to god not....
Do you have an old backup of your saves? If so use the level.dat and session.lock from there.
If you don't you can create a new world OVER the current one. It will not delete any previous chunks instead it will create a new spawn point in an unexplored area in your old map. Use a mapping program to find the location of your old buildings.
If chunks or other files do get corrupted the game will correct or overwrite them.