Silverlight 2.0 loading issue

I have developed a SL2 application for a client (whose computers are under pretty heavy lockdown via group policies). The SL2 application has worked fine for everyone except the client.

The client is using WinXP + IE7 and has the SL2 runtime installed.

On the client's machine the following error pops up:

Error: Unhandled Error in Silverlight
2 Application Code: 2103 Category:
InitializeError Message: 2103 An error
has occurred Code: 0

The client can load SLv1 websites like http://silverlight.net

The client can't load SLv2 websites like:

• http://memorabilia.hardrock.com/
• http://demos.telerik.com/silverlight/default.aspx
• http://timheuer.com/wpfe/versiontest/

What the client sees is a blank silverlight canvas but is able to right click and bring up the silverlight preferences menu.

Any ideas on how to debug this issue or has anyone else encountered this issue?

I should add that it works fine under firefox, but their IT department is unwilling to roll out FF to all the machines. The environment must be XP + IE7

Markup:

<object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%">
      <param name="source" value="/ClientBin/RosterUI.xap"/>
      <param name="onerror" value="onSilverlightError" />
      <param name="background" value="white" />
      <param name="minRuntimeVersion" value="2.0.31005.0" />
      <param name="autoUpgrade" value="true" />
      <param name="scaleMode" value="zoom" />
      <a href="http://go.microsoft.com/fwlink/?LinkID=124807" style="text-decoration: none;">
          <img src="http://go.microsoft.com/fwlink/?LinkId=108181" alt="Get Microsoft Silverlight" style="border-style: none"/>
      </a>
     </object>

From stackoverflow

• May be a reinstall of Silverlight runtime or IE7 can help.

  ericphan : We've already tried that. Still no go unfortunately

• I'd double check that the HTML markup that invokes the Silverlight control has the correct version number listed. If you use the ASP User Control, it should be fine. If you hand code the HTML, it should look something like this:

   <object data="data:application/x-silverlight," type="application/x-silverlight-2"
    id="silverlightHost" width="100%" height="100%">
    <param name="source" value="ClientBin/MYXAPFILENAME.xap" />
    <param name="onerror" value="onSilverlightError" />
    <param name="background" value="white" />
    <param name="initparams" value="<%= _initParams %>" />
    <param name="minRuntimeVersion" value="2.0.31005.0" />
    <param name="autoUpgrade" value="true" />
    <a href="http://go.microsoft.com/fwlink/?LinkID=124807" style="text-decoration: none;">
      <img src="http://go.microsoft.com/fwlink/?LinkId=108181" alt="Get Microsoft Silverlight"
        style="border-style: none" />
    </a>
  </object>
  

  ericphan : We are using HTML output. It seems correct to me. It does work on pretty much every other installation we've encountered. Just not on this client's network :( Here is the silverlight markup if you're interested

• Perhaps the client has an older build of SL2 installed. You can check their version number in the About tab in the Microsoft Silverlight Configuration panel (right click on the empty Silverlight app).

  If it's an older build, they'll need to install the RTM build.

  ericphan : Version on the client is 2.0.31005.0 so I don't think that's the issue

• After months of to-ing and fro-ing the issue has been resolved - although we still don't know the true underlying cause.

  The client's IT staff recently updated their transparent proxy server (which also filters content) and the silverlight app started working under IE.

  One of the changes made was to permit the downloading of DLL files (which is bundled in the XAP file). They think that is the cause, although I am not 100% convinced as it doesn't quite explain why it works in Firefox (assuming it also runs through the proxy)

• I have a Silverlight 3 application which I am trying to host on my Apache web server. I keep getting the following error message on my browsers (IE and Firefox) every time.

  Error: Unhandled Error in Silverlight Application Code: 2103 Category: InitializeError Message: 2103 An error has occurred. Code: 0

  It works when I run locally with IIS on my machine. All my namespaces are correct. I have also added the following MIME Types.

  application/manifest manifest application/octet-stream deploy application/vnd.ms-xpsdocument xps application/x-ms-application application application/x-ms-xbap xbap application/x-msdownload dll application/x-silverlight-app xap application/xaml+xml xaml