Failed-error-during-websocket-handshake-connection-header-is-missing 100%

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 .

If you are using Nginx as a reverse proxy, you must explicitly tell it to forward the Upgrade and Connection headers. By default, Nginx does not do this. Add or update your location block in your nginx.conf file: The error occurs when a client tries to

location /ws { proxy_pass http://your_backend_server; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; } Use code with caution. Copied to clipboard 🕸️ Apache Configuration Fix proxy_set_header Upgrade $http_upgrade

Here are the most common solutions based on your infrastructure: 🚀 Nginx Configuration Fix proxy_set_header Connection "upgrade"