Univetion APP upgrade not possible

UCS 5 latest Errata level - trying to upgrade EGroupware throws following error:

File "/usr/lib/python3/dist-packages/univention/appcenter/actions/__init__.py", line 167, in call_safe
    return cls.call(**kwargs)
  File "/usr/lib/python3/dist-packages/univention/appcenter/actions/__init__.py", line 175, in call
    return obj.call_with_namespace(namespace)
  File "/usr/lib/python3/dist-packages/univention/appcenter/actions/__init__.py", line 181, in call_with_namespace
    result = self.main(namespace)
  File "/usr/lib/python3/dist-packages/univention/appcenter/actions/upgrade.py", line 75, in main
    for app in apps:
TypeError: 'App' object is not iterable

Has somebody any ideas about this?