Troubleshooting

Common Problems

Encrypted connection issues

If you are using a self-signed certificate and are having trouble connecting and or seeing errors from websockify that look like this then see the websockify encryption page for workarounds:

handler exception: [Errno 1] _ssl.c:392: error:14094418:SSL routines:SSL3_READ_BYTES:tlsv1 alert unknown ca

Getting Diagnostic Output

You will need console logging support in the browser. Recent Chrome and Opera versions have built in support. Firefox has a nice extension called "firebug" that gives console logging support.

First, load the noVNC page with logging=debug added to the query string. For example vnc.html?logging=debug.

Then, activate the Javascript console in your browser. With Chrome it can be activate using Ctrl+Shift+J and then switching to the "Console" tab. With firefox+firebug, it can be activated using Ctrl+F12. In iOS (iPhone and iPad) you can activate the Debug Console via the main Settings app under Safari->Developer->Debug Console.

Now reproduce the problem. The console log output will give more information about what is going wrong and where in the code the problem is located.

If you suspect a problem with the web-socket-js flash emulator you can turn on debugging by setting window.WEB_SOCKET_DEBUG=1; in include/websock.js. This will enable Flash debug output to the web debug console.

Reporting Issues

If you file a issue/bug, it is very helpful for me to have the last page of console output leading up the problem in the issue report. Other helpful issue/bug information: browser version, OS version, noVNC git version, and VNC server name/version.