Using mmaps_generator :
They tell the server about item stats, spell effects, talent trees, and faction relations. Why they matter: WoW-WOLK-3.3.5a-Server-DBC-Maps-MMaps-VMaps-Wor...
Watch for missing file warnings.
Never mix pre-generated VMaps from one source with MMaps from another. Inconsistencies cause rare “desync” crashes. Using mmaps_generator : They tell the server about