Seems there are circumstances where a crash might arise when selecting extra slots for vertex groups:
Python: Traceback (most recent call last):
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\operators\bodyimport.py", line 14, in execute
ImportBodyBinary()
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 92, in __init__
FetchServerData('getBodyMeshInfo', self.gotBodyInfo)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 8, in __init__
self.executeJsonCall(expectBinaryResponse=expectBinary, params=params)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\sync_ops.py", line 19, in executeJsonCall
self.callback(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 14, in callback
self.readyFunction(json_obj.data)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 150, in gotBodyInfo
FetchServerData('getBodyVerticesBinary',self.gotVerticesData,True)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 8, in __init__
self.executeJsonCall(expectBinaryResponse=expectBinary, params=params)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\sync_ops.py", line 19, in executeJsonCall
self.callback(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 12, in callback
self.readyFunction(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 172, in gotVerticesData
FetchServerData('getBodyFacesBinary',self.gotFacesData,True)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 8, in __init__
self.executeJsonCall(expectBinaryResponse=expectBinary, params=params)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\sync_ops.py", line 19, in executeJsonCall
self.callback(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 12, in callback
self.readyFunction(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 190, in gotFacesData
FetchServerData('getBodyTextureCoordsBinary', self.gotTextureCoords, True)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 8, in __init__
self.executeJsonCall(expectBinaryResponse=expectBinary, params=params)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\sync_ops.py", line 19, in executeJsonCall
self.callback(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 12, in callback
self.readyFunction(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 204, in gotTextureCoords
FetchServerData('getBodyFaceUVMappingsBinary', self.gotFaceUVMappings, True)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 8, in __init__
self.executeJsonCall(expectBinaryResponse=expectBinary, params=params)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\sync_ops.py", line 19, in executeJsonCall
self.callback(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 12, in callback
self.readyFunction(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 238, in gotFaceUVMappings
self.afterMeshData()
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 472, in afterMeshData
FetchServerData('getBodyMaterialInfo',self.gotBodyMaterialInfo)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 8, in __init__
self.executeJsonCall(expectBinaryResponse=expectBinary, params=params)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\sync_ops.py", line 19, in executeJsonCall
self.callback(json_obj)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\fetch_server_data.py", line 14, in callback
self.readyFunction(json_obj.data)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 497, in gotBodyMaterialInfo
self.vgroupMaterials(mat)
File "C:\Users\Tomcat\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\MH_Community\mh_sync\import_body_binary.py", line 430, in vgroupMaterials
bpy.ops.object.vertex_group_set_active(group=key)
File "E:\Blender Foundation\Blender 2.93\2.93\scripts\modules\bpy\ops.py", line 132, in __call__
ret = _op_call(self.idname_py(), None, kw)
TypeError: Converting py args to operator properties: enum "body" not found in ('nippleTip', 'nipple', 'lips', 'fingernails', 'toenails', 'ears', 'scalp', 'genitals', 'Delete')
location: <unknown location>:-1
Seems there are circumstances where a crash might arise when selecting extra slots for vertex groups: