You were using MR Tech Toolkit, right? That extension provides an extensions button that looks like a green puzzle piece. Your extensions are not displayed properly?

Try this:
Exit Firefox and delete the following files from the profile:
extensions.ini
extensions.sqlite
compatibility.ini

Restart Firefox and see if the problem is fixed. If not, you might have to reinstall the problem extensions.

Key into the addressbar about:addons that will take you where you want.

Then bookmark it onto the bookmark toolbar by manually adding that address as a bookmark and ensure that the toolbar is displayed.

I tried removing the files and it didn't work. I also went through the Help pages and did the safe restart as well as disabling all extensions without luck. Any other suggestions?

It worked like a charm! I'm so happy to have my button back!!!

THANKS!

Glad you sorted it out. Thanks for posting back.

I also have Firefox 22 and cannot get my Add-on Toolbar to display and no longer have the puzzle icon. I tried the bookmark solution but only get a page that displays the add-ons. I am not using MR Tech Toolkit. I have downloaded and previously used DownloadHelper as a seperate add-on but now cannot find it after updating to Firefox 22.  ?????

Bookmarking or using about:addons is merely a shortcut or alternative method of getting to the addons page.

The addons toolbar at the bottom edge of the page can be turned on and off from a menu or by keyboard shortcuts, but probably not many add-ons actually make use of it.

• See Customize Firefox controls, buttons and toolbars_how-do-i-show-and-hide-the-different-toolbars
• Use 'Firefoxbutton -> View -> Toolbars -> Add-on bar,
  or Ctrl + / or just right click an empty space on a toolbar

I have just tried download helper. That shows up in my Tools menu. I have the menu toolbar displaying. If you need to display the menu toolbar temporarily try pressing the Alt key. Presumably the options also appear in the FirefoxButton in one of its menus.

You can also right-click on the navigation toolbar and click "Add-on bar" from the context menu.

There is an add-on called

about:add-ons Launcher 1.1

You will find it if you do search. Fixed me right up!

KJ