Have you taken a look at the following help article: http://www.telerik.com/help/aspnet-ajax/editor-migration-from-radeditor-classic-to-radeditor-prometheus.html
? It lists properties used in RadEditor Classic and the new ones they correspond to in the AJAX version. Xhtml
is now Content
. It is not a matter of adding more references, but of using the correct API members.
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the RadControls for ASP.NET AJAX, subscribe to the blog feed