Silverlight 5.0 to 5.1.20124.* has been blocked for your protection.

Why was it blocked?
This plugin is outdated and is potentially insecure. Affected users should go to the plugin check page and update to the latest version.
Who is affected?
All Firefox users who have this plugin installed.
What does this mean?

The problematic add-on or plugin will be automatically disabled and no longer usable.

When Mozilla becomes aware of add-ons, plugins, or other third-party software that seriously compromises Firefox security, stability, or performance and meets certain criteria, the software may be blocked from general use. For more information, please read this support article.