McAfee Site Advisor has been blocked for your protection.

Why was it blocked?
Versions of the McAfee Site Advisor extension older than 3.4.1.195 have a major memory leak problem that can make Firefox consume large amounts of memory and possibly crash after extensive use. All users should upgrade their McAfee software to the latest available version, which fixes the memory leak and isn't affected by this block.
Who is affected?
All Firefox users who have installed the McAfee Site Advisor on Windows and have a version older than 3.4.1.195. Versions 3.4.1.195 and above should be unaffected by this block.
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.