Because Security issues in the WebSockets protocolFirefox and Opera have disabled support for WebSockets for their upcoming releases Firefox 4 and Opera 11. We covered how to enable WebSockets in Opera 11. Firefox 4 Beta 8 will ship with WebSockets support disabled by default if you want to experiment with WebSockets in Firefox 4 , see how to do this.
Enabling WebSockets in Firefox 4 Beta 8
1. Type about:config in the address bar and continue clicking “I’ll be careful, I promise”
2. Define network.websocket.enabled value to ‘true’ and set network.websocket.override-security-block preferences for ‘true’.
3. Restart the Firefox browser.