TypeError: __init__() missing 1 required positional argument: 'port'

[julien-duponchelle]

https://app.getsentry.com/gns3/gns3-server/issues/120100329/

TypeError: __init__() missing 1 required positional argument: 'port'
  File "gns3server/web/route.py", line 179, in control_schema
    yield from func(request, response)
  File "gns3server/handlers/api/docker_handler.py", line 106, in start
    yield from container.start()
  File "gns3server/modules/docker/docker_vm.py", line 256, in start
    yield from self._start_ubridge()
  File "gns3server/modules/base_vm.py", line 420, in _start_ubridge
    yield from self._ubridge_hypervisor.start()
  File "gns3server/ubridge/hypervisor.py", line 158, in start
    raise UBridgeHypervisor("Could not start ubridge: {}\n{}".format(e, ubridge_stdout))

[julien-duponchelle]

I don't see why the user got the crash perhaps an old dev version