Silverlight 3 – Out of Browser Applications with Cached Extensions

Yesterday, by mistake, I tried to combine 2 features of Silverlight 3 that don’t work together. Unfortunately for me, it was in front of a bunch of people 🙂

I’d been briefly showing how you can decrease the size of a Silverlight 3 XAP by using the new project option in Visual Studio to reduce XAP size. The way this works is that;

  1. Microsoft assemblies that would usually be built into your XAP can be downloaded from
  2. This reduces the size of your XAP
  3. This benefits all applications as they don’t all end up packaging assemblies that are common

So, generally, that’s all good stuff.

However…it doesn’t work when you combine it with Out of the Browser applications – in the current beta when you take an application that’s using cached extensions out of the browser you’ll find that it doesn’t work ( for me, what happens is that the application doesn’t display anything when it’s taken out of the browser ).

Now, I’d never actually meant to try and combine these 2 things in my demo – it was something that I’d done by mistake and hadn’t noticed myself doing it 🙂 However…it did highlight that these things don’t work together so at least I ( and everyone else who was watching 🙂 ) managed to learn something from it and I thought I’d share that here in case anyone’s searching and hitting the same thing.