Firefox/Tools > Add-ons will open the Add-ons manager in a tab with the URL about:addons

Or you can use { Ctrl + Shft + A } from the keyboard.

Following the instructions posted here, the addons manager opens IN a tab on the tab bar.

OK, I'm there, but I can't continue. Extensions ="You don't have any add-ons of this type installed." "Appearance" ="Default Theme"

Do I have to Uninstall Firefox and the Re-Install? How do I Re-Install if I can't get on line?

Which extension(s) are you trying to remove?

If Extensions shows "You don't have any add-ons of this type installed." then there are no extensions installed.

What exactly is your problem?

Please read this thread:

https://support.mozilla.com/en-US/questions/894177

I installed the "Ant Video Downloader : The best video downloader". Now my Youtube Video will not play.

http://www.ant.com/video-downloader

If that extension is Firefox from playing videos then you need to uninstall it.

• https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

I have switched back to Ubuntu 10.04 and the problem is now gone. I'm now running Firefox 3.6.24 without any problems.