Adobe Reader 15.006.30244 and lower has been blocked for your protection.

Why was it blocked?
Old versions of the Adobe Reader plugin have known vulnerabilities. All users are strongly recommended to check for updates on Adobe's Reader page.
Who is affected?
All 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.