Error 1006 when closing websocket, why?

Question

PHP

Ubuntu 16.04, LAMP stack, using workerman library to work with websocket . The port is open in the firewall (ufw). The connection is established correctly, messages are sent, but when you try to cleanly close the connection through close, both from the js side and from the server side, the client connection is closed with error 1006, without other details. OpenVpn is also installed on the server, but on a different port. Any ideas what it could be and maybe some additional debugging steps to concretize/find out the cause?

Answer 1

Error 1006 indicates that the connection was closed abnormally (i.e., without sending a close frame) when a status code is expected.