Related Github issues:
WebSocket connection error
I got this error in browser client, don't know what it will take affect and how to solve?
WebSocket connection to 'ws://<myhost>/socket.io/?EIO=3&transport=websocket&sid=wW5Z4UKR9a_ZHKHkAAAF' failed: Error during WebSocket handshake: Unexpected response code: 400
which port it's using, I just open the port 4567 in firewall.