Silverlight: Why do I get "Internet Explorer cannot display the webpage"?

Sometimes I create a Silverlight project and I get "Internet Explorer cannot display the webpage" when I try and run it. If I keep pressing refresh (usually 2 or 3 times) the page loads ok. Occasionally, I also get the message dialog:

Webpage开发者_如何学编程 Error

Line: 56 Error: Unhandled Error in Silverlight Application Code: 2104

Category: InitializeError

Message: Could not download the Silverlight application. Check web server settings

Other Silverlight projects still work fine. Anyone know what causes this problem with some projects ?

---

This has worked for me:

Debugging Silverlight applications with IE9 beta