Error in seahub when accessing group shares

Running Seafile 7.0.4 on a Raspberry Pi, the Seahub Web UI shows an Error when clicking on “Shared with Groups” and then selecting one of the groups (i.e., the URL my-seafile-server.tld/group/1/ (or a different number)).

It works, if I select “All groups” instead of a specific one.

seahub.log logs the following error:

2019-08-05 15:21:00,647 [ERROR] django.request:135 handle_uncaught_exception Internal Server Error: /api/v2.1/groups/3/libraries/
Traceback (most recent call last):
  File "/home/seafile/seafile-server-7.0.4/seahub/thirdpart/Django-1.11.16-py2.7.egg/django/core/handlers/exception.py", line 41, in inner
    response = get_response(request)
  File "/home/seafile/seafile-server-7.0.4/seahub/thirdpart/Django-1.11.16-py2.7.egg/django/core/handlers/base.py", line 249, in _legacy_get_response
    response = self._get_response(request)
  File "/home/seafile/seafile-server-7.0.4/seahub/thirdpart/Django-1.11.16-py2.7.egg/django/core/handlers/base.py", line 187, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/home/seafile/seafile-server-7.0.4/seahub/thirdpart/Django-1.11.16-py2.7.egg/django/core/handlers/base.py", line 185, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/seafile/seafile-server-7.0.4/seahub/thirdpart/Django-1.11.16-py2.7.egg/django/views/decorators/csrf.py", line 58, in wrapped_view
    return view_func(*args, **kwargs)
  File "/home/seafile/seafile-server-7.0.4/seahub/thirdpart/Django-1.11.16-py2.7.egg/django/views/generic/base.py", line 68, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/seafile/seafile-server-7.0.4/seahub/thirdpart/djangorestframework-3.3.3-py2.7.egg/rest_framework/views.py", line 466, in dispatch
    response = self.handle_exception(exc)
  File "/home/seafile/seafile-server-7.0.4/seahub/thirdpart/djangorestframework-3.3.3-py2.7.egg/rest_framework/views.py", line 463, in dispatch
    response = handler(request, *args, **kwargs)
  File "/home/seafile/seafile-server-7.0.4/seahub/seahub/api2/endpoints/utils.py", line 42, in _decorated
    return func(view, request, group_id, *args, **kwargs)
  File "/home/seafile/seafile-server-7.0.4/seahub/seahub/api2/endpoints/group_libraries.py", line 106, in get
    if '@seafile_group' in email:
TypeError: argument of type 'NoneType' is not iterable

Thanks for fixing!

Do you see any error messages in ccnet.log and seafile.log?

No, there are no error messages in these or any other log files.