silverlight not installing

I have recently installed latest avast endpoint protection suite plus on a companies server (windows server 2008 R2 standard) - when trying to finish the installation I get a browser page telling me to click here to install MS silverlight - after succesful installation message and refresh browser page message says “an add-on for this website failed to run”…

Any ideas please ??

Please ask here: http://forum.avast.com/index.php?board=33.0