The Telerik UI for WPF product is distributed in two alternative sets of assemblies that differ in the theming mechanism that they use - StyleManager
. If the latter assemblies are used (they are the recommended ones), the XAML resources need to be merged in the application resource scope either from a theme assembly, or from separate resource dictionaries. If they are not merged, controls are not visualized, as there are no XAML resources in the control assemblies, and they are blank. The mentioned article describes the process for using the Implicit theming assemblies. If you are still not sure about the set of assemblies you are currently using, you can check it by looking at the assembly's file description. The one that use implicit styles have the "no XAML" text in the description.
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