Checking the plugins now and then is a good idea. If any are listed as unknown or research, do not worry about them.

You can also go to this page, and select Watch This; https://support.mozilla.org/en-US/forums/plug-check-page-discussions

FredMcD said

Checking the plugins now and then is a good idea. If any are listed as unknown or research, do not worry about them. You can also go to this page, and select Watch This; https://support.mozilla.org/en-US/forums/plug-check-page-discussions

Thank you for your reply. My issue is that there are plugins that aren't listed at all. What should I do with those?

Rota said

https://www.mozilla.org/en-US/plugincheck/ only shows some of my plug-ins. Are these the only ones I need to update?

Not entirely. If you have set a user-installed plugin such as Flash to Never activate, it will not be listed on the Plugin check page, so you would need to set it (and other plugins) to Always activate or Ask to activate in order to be checked.

That does not include the "internal" plugins however that come bundled, such as the Widevine, Primetime and H264 codecs/modules - they are never listed there and are updated in a different way if needed.

Only a few plugins are known on the plugin check website. You will have to check the website of not recognized plugins yourself on the website of the provider of these plugins.

• https://plugins.mozilla.org/en-us/plugins_list.json

Adobe Flash Player
Adobe Reader
Adobe Shockwave Player
Cisco Web Communicator
Java Runtime Environment
QuickTime Plug-in
RealPlayer
Silverlight Plug-In
VLC Multimedia Plug-in

Note if you were using the Win64 Firefox (from www.mozilla.org/firefox/all/ ) then only the two external 64-bit Flash Player and Silverlight Plugins are white listed to run in Win64 Firefox.