Microsoft Silverlight is a plugin used by some websites to display multimedia content. This article describes how to check whether you have Silverlight installed and how to install or update it.
Silverlight is not available for the Linux platform and the only open source implementation of Silverlight, called Moonlight, is not developed anymore. It can be still compiled from source but it is not recommended to use it. More information can be found at the Moonlight installation page.
Mozilla blocks older versions of Silverlight, causing sites like Netflix to display a message asking you to install Silverlight. To fix this, please update your installation of Silverlight to the latest version by visiting Microsoft's Get Microsoft Silverlight page.
In some cases, this may not resolve the problem and you will need to manually activate the Silverlight plugin:
Click the menu button
and choose Add-ons. The Add-ons Manager tab will open.
In the Add-ons Manager tab, select the Plugins panel.
Find Silverlight in the list of plugins and select Always Activate in its drop-down menu.