Silverlight for Mac OS X between 5.1 and 5.1.20124.* (click-to-play) has been blocked for your protection.

Why was it blocked?

Old versions of this plugin are potentially insecure and unstable. All affected users should visit the plugin check page to look for updates for their Silverlight plugin.

Who is affected?

All Firefox users who have these versions of the 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.