How to solve Unhandled Error in Silverlight Application Code: 2104

How to solve Unhandled Error in Silverlight Application Code: 2104


Tags: IIS, MimeTypes

I’ve found that I get this error every time I upload a Silverlight application to a new webserver. IIS does not have the correct settings by default.

The Problem: You ftp a Silverlight App to an IIS website, go to the website in a browser, and get the following error:

Message: Unhandled Error in Silverlight Application

Code: 2104

Category: InitializeError

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



The Cause: The Silverlight Mime types (.xaml, .xap and .xbap) are not listed in that websites registered mime types, therefore IIS will not send those files to the browser.



The Solution: Open IIS on the server, go to HTTP headers, click on Mime Types, click “Add New” and add the following:



Extension – Mime Type

.xaml – application/xaml+xml

.xap – application/x-silverlight-app

.xbap – application/x-ms-xbap