Ok, there are several problems listing this one-
1. You did not repack it to an MRS file
2. You cannot make a NEW map unless it is an private server.. rename the map to an existing one and overwrite.
3. You don't have all parts in it.. maybe you deleted some of them.
I Think the problem is nr.2 If it is a Private Server map.. you can just give it the name you want and put it in.. if it is a normal gunz you have to rename it to the map you've edited and overwrite (backup first)
-Demonite-