I encountered the same problem before. The problem may be caused by:
you didn't enable the google plus api
the social_auth_url in app.conf doesn't match your website url. (If the callback url that you registered in google developer console is http://example.com/login/google/access, the social_auth_url should be set as http://example.com/)
Error: redirect_uri_mismatch
The redirect URI in the request: http://*****.com/login/google/access did not match a registered redirect URI.
Learn more
Request Details scope=email profile https://www.googleapis.com/auth/plus.login response_type=code redirect_uri=http://******.com/login/google/access access_type=offline approval_prompt=auto
That’s all we know.
I do't know why this happend.