I changed it: registry.addEndpoint("/onlineusers").setAllowedOrigins("*") .withSockJS();to: registry.addEndpoint("/onlineusers").setAllowedOrigins("*");and Java deployment failed When using SockJS, I have the error: WebSocket connection to "ws://sepiqon.heliohost.org/sepiqon_server2SockJS/onlineusers/.../.../websocket" failed: Error during WebSocket handshake: Unexpected response code: 400, (and adres: "wss://sepiqon.heliohost.org/sepiqon_server2/onlineusers/.../.../websocket") without SockJS, I tried to connect to the url: wss://sepiqon.heliohost.org/sepiqon_server2/onlineusers but I don't know if the url works: wss://sepiqon.heliohost.org/onlineusers (https://www.helionet.org/index/topic/37604-java-websocket-connection-failure/?p=168706) Please help with SockJS I cannot connect to the last two addresses, Please help file .war deployed: sepiqon_server2SockJS.war file without SockJS: sepiqon_server2.war Please help!