Ensure mod_proxy and mod_proxy_wstunnel are enabled. Use a RewriteRule in your VirtualHost to pass WebSocket traffic:
The error occurs when a client tries to establish a WebSocket connection, but a network intermediary (like a reverse proxy or load balancer) strips out the required HTTP headers needed to upgrade the connection from standard HTTP to WebSockets . Ensure mod_proxy and mod_proxy_wstunnel are enabled
Managed services often strip headers; ensure WebSocket support is enabled: : Enable Stickiness for polling fallbacks. Azure App Service : Toggle WebSockets on in configuration. 💻 Local Development Protocol : Ensure using ws:// or wss:// . { transports: ['websocket'] }) .
Which or server framework are you currently using to host this application? Ensure mod_proxy and mod_proxy_wstunnel are enabled
: Force websocket transport: io('url', { transports: ['websocket'] }) .