Orgrimmar2.wmo dont open in blender

[Farrarie]

when I try to import this wmo in blender I get this error = here is the wmo World.zip

here is the error Traceback (most recent call last): File ":\blender-2.78c-windows64\2.78\scripts\addons\io_scene_wmo_init_.py", line 163, in execute import_wmo.import_wmo_to_blender_scene(self.filepath, self.load_textures, self.import_doodads, self.group_objects) File "\blender-2.78c-windows64\2.78\scripts\addons\io_scene_wmo\wmo\import_wmo.py", line 56, in import_wmo_to_blender_scene group.load_object(obj_name, import_doodads) File "\blender-2.78c-windows64\2.78\scripts\addons\io_scene_wmo\wmo\wmo_group.py", line 458, in load_object mesh.polygons[i].material_index = material_indices[mat_id] KeyError: 0

location: :-1