Those errors usually mean websockets are not proxied correctly, make sure your nginx setup is correct. If you are using cloudflare you need to disable acceleration. They don't support websockets on smaller plans.
#BOOM!
Fixed
Thanks a lot for your help guys and sorry for the false alarm, maybe the plugin in Github should have this warning. I know that is a dumb mistake and most of web developers may be aware of it but just in case.
