QuickTime Plugin 7.6.5 and lower (click-to-play), Mac OS X has been blocked for your protection.

Why was it blocked?
Old versions of the QuickTime plugin are known to be insecure and cause stability problems. All users are recommended to update to the latest version available. You can check for updates in the plugin check page.
Who is affected?
All Firefox users who have affected versions of the QuickTime 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.