Wtf are you talking about? It always worked fine for me.
Just to be sure I understood : are you talking about all your custom abilities? Or you can't see any ability in the object editor? Did that happen after you moved the file in the W3 directory or after you moved it from the W3 directory to elsewhere?
If you say that putting the file in W3 directory removed all your abilities in the object editor, I'm sorry because I never thought it could happen. Still, if you haven't saved yet, your abilities are always in your map and removing the .slk files will bring them back. If you use the JNGP, there are also backups of your map in the jassnewgenpack5d\backups directory (and when you use "test map", it also creates a backup as Warcraft III\Maps\Test\WorldEditTestMap.w3x).