Why would you need to debug Silverlight applications running out of the browser? One reason is to test applications that use Elevated Trust. Let us see how simple it is to debug applications running out of the browser.
Right click the project in Solution Explorer > Properties > Silverlight tab. Make sure the ‘Enable running application out of the browser’ is checked
If you go to the Debug tab, you will observe that the ‘Out-of-browser application’ radio is already selected for you
That’s it. Set a breakpoint, run the application and step through the code.