I'm currently logged in and it is completely functional. Maybe it is a browser issue? I have tested on the latest Chrome, Chromium, Firefox, and Firefox DE, but it does not work on Pale Moon (a less frequently updated fork of Firefox).
One thing I notice is that you are trying to run with the run.sh script from the git directory, but you should be using the command
c9vnc. That script is installed as part of the application; in fact, you could completely delete the
cloud9-vnc directory completely once you run the installer.