If you don't know what the JNGP folder is then you are probably not working with JassNewGenPack.
Take a look
here if you want to start using JNGP.
It has a lot of usefull functionality that the normal world editor does not have.
Including a backup folder which saves your maps every ... minutes to make sure you have several copies of the maps you are working on.
This way when your map becomes corrupt you can go through the backup folder to find one of the most recent versions which didn't become corrupt.
If you would be abled to upload the map then we can all take a look at the archive of your map to see if we can retrieve the corrupt data of your map.
However, this is not always the case.
Most of the time it's impossible to retrieve a corrupt map entirely, so be prepared...
Sometimes the least we can do is retrieve parts of the map.
Such as object data, terrain data or trigger data
(Usually obfuscated Jass script. It's very rare to fully retrieve GUI triggers).
However usually, nothing at all can be retrieved.
