Download a MPQ browser and extract the maps from inside. Look on TheHiveWorkshop for a MPQ browser and edit away.
Download the program below and under the windows tab, look for MPQ Browser locate you War3 or War3x.MPQ file and open the Maps subfolder. Then right click on the map and click export.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.