Turn on Silverlight support in Plesk

What is Silverlight?

Silverlight was a plug-in from Microsoft. It played video and ran small web apps inside a browser. It is old now and most browsers no longer support it. Some older sites still use it, so this guide is for them.

Plesk is a control panel, a web page where you manage your hosting. Silverlight files end in .xap. A server must know how to send these files. That is called a MIME type, which is a label that tells the browser what kind of file it receives.

Steps

1. Log in to Plesk. Your site must be on Windows hosting.
2. Click Websites & Domains.

   

3. Find your domain and click IIS Settings. IIS is the Windows web server program.

   

4. Look for the MIME types section. On some versions it is under Additional settings. Click Add MIME type or Add.

   

   

5. In the extension box type .xap.
6. In the type box type application/x-silverlight-app.
7. Click OK.
8. If your site uses Silverlight video, repeat for .xaml with the type application/xaml+xml.

If you do not see these options, you can instead add the setting in your site's web.config file. Back up the file first. Add this inside the system.webServer section:

<staticContent>
  <mimeMap fileExtension=".xap" mimeType="application/x-silverlight-app" />
</staticContent>

This tells the server how to label .xap files.

Test it

1. Open the page that holds your Silverlight content.
2. If the browser asks, allow the plug-in.
3. Clear your browser cache if you see the old error.

Still stuck? Open a support ticket.

Quick recap

• Silverlight is an old plug-in for web apps and video.
• The server needs a MIME type for .xap files.

  

• Add it in IIS Settings or in web.config.
• Back up before editing files.
• Modern browsers may not run Silverlight at all.