The WebSocket is closed before the connection is established error message that is outside of our control.
For more information see this StackOverflow answer
If yes, then there's nothing more than can be done.
If not, then if you are using Google Chrome you may need to restart your browser. We've seen that after Chrome updates there is sometimes a network issue which stops WebSocket connections from succeeding.
If you are not using Google Chrome or a Google Chrome restart did not help then please follow the Pusher Connection FAQ.