Hi Muhammad Saqib,
You can edit only the properties of the external pages, but not the actual content. Also, make sure that there is no any js in the external page that catches the click event of each <a> element or button.
You could try to use http://www.telerik.com/default.aspx as an external resource just for the test.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items.