Can't sign in via Google using outlinemaps.org domain

[papousek]

[2016-04-14 07:19:07,676] ERROR "Internal Server Error: /complete/google-oauth2/"
Traceback (most recent call last):
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/django/core/handlers/base.py", line 149, in get_response
    response = self.process_exception_by_middleware(e, request)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/django/core/handlers/base.py", line 147, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/django/views/decorators/cache.py", line 57, in _wrapped_view_func
    response = view_func(request, *args, **kwargs)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/django/views/decorators/csrf.py", line 58, in wrapped_view
    return view_func(*args, **kwargs)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/social/apps/django_app/utils.py", line 51, in wrapper
    return func(request, backend, *args, **kwargs)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/social/apps/django_app/views.py", line 28, in complete
    redirect_name=REDIRECT_FIELD_NAME, *args, **kwargs)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/social/actions.py", line 43, in do_complete
    user = backend.complete(user=user, *args, **kwargs)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/social/backends/base.py", line 41, in complete
    return self.auth_complete(*args, **kwargs)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/social/utils.py", line 229, in wrapper
    return func(*args, **kwargs)
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/social/backends/oauth.py", line 375, in auth_complete
    state = self.validate_state()
  File "/usr/local/share/.virtualenvs/outlinemaps-production-2/lib/python3.5/site-packages/social/backends/oauth.py", line 88, in validate_state
    raise AuthStateMissing(self, 'state')
social.exceptions.AuthStateMissing: Session value state missing.