Thankyou sir for replying.
I added the control from toolbox, but still it is showing the same error.
What should i do now?
After adding radpanelbar it is showing error as:
Error 16 The tag 'RadPanelBar' does not exist in XML namespace 'http://schemas.telerik.com/2008/xaml/presentation'.
It is also showing WARNINGS like this : The primary reference "Telerik.Windows.Controls" could not be resolved because it has an indirect dependency on the .NET Framework assembly "System, Version=220.127.116.11, Culture=neutral, PublicKeyToken=7cec85d7bea7798e" which has a higher version "18.104.22.168" than the version "22.214.171.124" in the current target framework. TutorialViewChangeEvents