We investigate the problem with the Server 2012 and found what is causing it. It is the change in the default behavior in IIS 8. It doesn't add the WCF Services HTTP Activation by default. It seems that we don't make that check during the installation. We will investigate and try to fix it. Until we fix the automatic configuration you need to go and add enable form the Server 2012 Features HTTP Activation.
the Telerik team