Quick Fix: Silverlight Application showing as a blank screen

I just diagnosed and fixed a problem with my Silverlight application that I’ve hit often enough to make me think it’s worth sharing my approach.

The problem was a simple one. When I deployed my application, and browsed to a page that should have displayed a Silverlight control, all I saw was a blank page.

So I fired up the diagnoser of all problems Http, the excellent Fiddler, and reloaded my page. This is what I saw:

In glaring red, Fiddler shows that my Silverlight control made a request to download one of its dependencies (which are all packaged in zip files and stored in the ClientBin folder), and was told it was not available – a HTTP 404 error.

So the fix was obvious: just add the missing file to my installer. Sorted!