Can't log in to HyperKitty with Google

The login page presents three methods: Login by email which is Persona and works fine; Yahoo which also works to log in with a Yahoo account, and Google which produces a 500 Server error with the following log message.

How can this be made to work?

ERROR 2016-03-24 21:13:09,747 base 21823 140486276622144 Internal Server Error: 
/login/google/
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/Django-1.9.4-py2.7.egg/django/core/handlers/base.py", line 149, in get_response
    response = self.process_exception_by_middleware(e, request)
  File "/usr/local/lib/python2.7/dist-packages/Django-1.9.4-py2.7.egg/django/core/handlers/base.py", line 147, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/usr/local/lib/python2.7/dist-packages/Django-1.9.4-py2.7.egg/django/views/decorators/cache.py", line 57, in _wrapped_view_func
    response = view_func(request, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/python_social_auth-0.2.14-py2.7.egg/social/apps/django_app/utils.py", line 51, in wrapper
    return func(request, backend, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/python_social_auth-0.2.14-py2.7.egg/social/apps/django_app/views.py", line 19, in auth
    return do_auth(request.backend, redirect_name=REDIRECT_FIELD_NAME)
  File "/usr/local/lib/python2.7/dist-packages/python_social_auth-0.2.14-py2.7.egg/social/actions.py", line 28, in do_auth
    return backend.start()
  File "/usr/local/lib/python2.7/dist-packages/python_social_auth-0.2.14-py2.7.egg/social/backends/base.py", line 35, in start
    if self.uses_redirect():
  File "/usr/local/lib/python2.7/dist-packages/python_social_auth-0.2.14-py2.7.egg/social/backends/open_id.py", line 239, in uses_redirect
    return self.openid_request().shouldSendRedirect()
  File "/usr/local/lib/python2.7/dist-packages/python_social_auth-0.2.14-py2.7.egg/social/backends/open_id.py", line 248, in openid_request
    err
AuthException: OpenID discovery error: HTTP Response status from identity URL host is not 200. Got status 404