Unable to do partymode

[ba...@okotokscomputers.com]

I am unable to get my app to do partymode when all players are individual (not grouped)

When there is a power outage all players (26) disconnect from their groups and become individual players. My app checks for this and is set to automatically restore the groups (which for some reason only works when everything is in partymode)

However getting the players in partymode does not work using Player =  SoCo('192.168.75.101") Player.partymode()

i get an error 

Traceback (most recent call last):

  File "C:\Sonos\Test.py", line 13, in <module>

    LE.partymode()

  File "C:\Users\okotokscomputers\AppData\Roaming\Python\Python36\site-packages\soco\core.py", line 855, in partymode

    [zone.join(self) for zone in self.visible_zones if zone is not self]

  File "C:\Users\okotokscomputers\AppData\Roaming\Python\Python36\site-packages\soco\core.py", line 838, in visible_zones

    self._parse_zone_group_state()

  File "C:\Users\okotokscomputers\AppData\Roaming\Python\Python36\site-packages\soco\core.py", line 753, in _parse_zone_group_state

    cache_timeout=5)['ZoneGroupState']

  File "C:\Users\okotokscomputers\AppData\Roaming\Python\Python36\site-packages\soco\services.py", line 593, in GetZoneGroupState

    return self.send_command('GetZoneGroupState', *args, **kwargs)

  File "C:\Users\okotokscomputers\AppData\Roaming\Python\Python36\site-packages\soco\services.py", line 357, in send_command

    self.handle_upnp_error(response.text)

  File "C:\Users\okotokscomputers\AppData\Roaming\Python\Python36\site-packages\soco\services.py", line 417, in handle_upnp_error

    error_xml=xml_error

soco.exceptions.SoCoUPnPException: UPnP Error 501 received: Action Failed from 192.168.75.101

I have tried this with all my players, they all give the same error....

Any ideas? This has been annoying since i always need to use the sonos app to do partymode (defeats the purpose of automating)