Add-ons that cause stability or security issues are put on a blocklist
Add-ons (extensions, themes, and plugins) that violate Mozilla's add-on guidelines are put on a "blocklist".
Table of Contents
What does the blocklist do?
Disables unsafe add-ons
Firefox will block the unsafe add-on from loading and present you with the following message:
To prevent these add-ons from running, click .
Blocks unsafe add-ons from being installed
When you try to install an unsafe add-on that is on the blocklist, Firefox will block the installation and display the message:
Prevents plugins from running automatically
Firefox can prevent a plugin from running automatically (which prevents many issues). When Firefox blocks a plugin you'll see a message similar to this:
You can then choose to run the plugin or update it (if an update is available). To learn more, see Why do I have to click to activate plugins?
Beginning with Firefox version 52, support has ended for all NPAPI plugins except for Adobe Flash. See this compatibility document and this article for details.
Steps to take
If the installed add-on is disabled
Extension or theme
Click the menu button
and choose . The Add-ons Manager tab will open.
- In the Add-ons Manager tab, select the panel.
- On the "Tools for all add-ons"
menu, make sure that the menu item is checked.
Plugin
Check to see if there's an updated version of your plugin. If there are no plugin updates available, you may need to contact the developer of the plugin that was blocked.
Installation blocked
If you were blocked from installing an add-on, check to see if there is an updated version of the add-on you were trying to install.
What unsafe add-ons are on the blocklist?
See the list of blocked add-ons.
Last Update: 2017-11-08