As stated in http://docs.telerik.com/devtools/wpf/controls/radrichtextbox/getting-started/getting-started I added the below references to my WPF project and a simple XAML declaration of RadRichTextBox and the project builds fine and RadRichTextBox is visible in Visual Tree while debugging but it is not rendered on the screen using both VS 2015 and VS 2017. If I replace it with standard WPF RichTexBox everything works fine. I am unable to find anything on this problem in forums or in documentation so what is the problem here and how to resolve it?
Sample project attached (It's a zip file but it's not allowed so I changed the extension to jpg).
Telerik.Windows.Controls
Telerik.Windows.Data
Telerik.Windows.Documents
Telerik.Windows.Documents.Core
Telerik.Windows.Documents.Flow
System.ComponentModel.Composition