If you are getting a continuous "Loading", click on one of the other items in the left column of the Add-ons Manager (Extensions, Appearance, or Plugins). There is a minor glitch that should occur only on the first opening of the Add-ons Manager window/tab.

You can always look at new Add-ons and use the Search at the top of the page, by going to: https://addons.mozilla.org/en-US/firefox/

If this reply solves your problem, please click "Solved It" next to this reply when signed-in to the forum.

Not related to your question, but...

You need to update some plug-ins:

• Plug-in check: https://www-trunk.stage.mozilla.com/en-US/plugincheck/
• Shockwave Flash (Adobe Flash or Flash): Updating Flash in Firefox

Installed flash player, problem solved!!

To help other users find solutions, please return and sign-in to the forum with your user name and password:

• click on "Solved It" next to the reply ABOVE that BEST solved your question
• DO NOT click "Solved It" next to this reply

Thanks

What do I do when the add - manager refuse to start? Thanks

-> Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Check and tell if its working.