Firefox 29 moved all the icons and controls from the Add-on bar up to the main toolbar. If they don't all fit, there's an overflow drop-down, or you might find the icon in the Customize panel.

• Customize Firefox controls, buttons and toolbars

A few extensions seem to require that their button be on the Add-on bar and remove themselves from the main toolbar. If this is one of those, you probably need an extension to re-create the Add-on bar. Here are two I've seen:

• The Addon Bar (restored): https://addons.mozilla.org/firefox/addon/the-addon-bar/
• Classic Theme Restorer: https://addons.mozilla.org/firefox/addon/classicthemerestorer/ (very comprehensive customizer for users who prefer an earlier look)

You should contact the add-on authors and let them know it needs to be updated. The add-on uses the status bar, which was deprecated in Firefox 4 and has now been removed in Firefox 29.

• https://developer.mozilla.org/en-US/Firefox/Australis_add-on_compat
• https://developer.mozilla.org/en-US/Firefox/Releases/4

As a workaround, you can install one of the add-ons that provides a replacement add-on bar, which will in turn also provide a replacement status bar shim.

• https://addons.mozilla.org/firefox/addon/the-addon-bar/
• https://addons.mozilla.org/firefox/addon/status-4-evar/versions/
• https://addons.mozilla.org/firefox/addon/classicthemerestorer/

Thanks for the quick replies.

Installing the-addon-bar solved the problem