Extensions for Firefox, such as the Google Toolbar, include a list of compatible Firefox versions. Currently, the Google Toolbar only goes up to Firefox 4. However, people have tested and it actually works on Firefox 5, so there are two workarounds:

(1) Edit a file to revise the range of compatible versions

(2) Install an add-on that lets you ignore the range of compatible versions

This thread has info on both approaches: google toolbar does not work with firefox 5.0. why not! | Firefox Support Forum | Firefox Help.

Any luck?

There is new information from Google since a month ago, they took there sweet time to say they would no longer support their toolbar. Supporting their extension only on older versions of Firefox is not really support, and that will obvious run out. Google dropped support because they said the functionality was already in Firefox (they are including extensions in that assessment).

Google Chrome does not have the Google Toolbar and never did. Google kind of leads the pack on not much in the way of toolbars for the browser itself. Really glad that Firefox is customizable and that we can still have basic functional toolbars. I personally never install any third party toolbars.

The Google Toolbar is no longer supported by Google in Firefox 5 and up, you may be able to get what you want from it for a limited time, the directions to install the Google Toolbar were posted before Google actually announced dropping support.

• Enable Google Toolbar in Firefox 5
  http://googlesystem.blogspot.com/2011/06/enable-google-toolbar-in-firefox-5.html
• the-edmeister posted a brief evaluation of the situation
  https://support.mozilla.com/en-US/questions/841736

In any case you can find several alternative solutions, and you can start working on them now, see

• "Using Google Toolbar features without toolbars"
  http://kb.mozillazine.org/Using_Google_Toolbar_features_without_toolbars

If this solves your problem then mark as solved, if there is an aspect that is not covered directly or through searching extensions on that page, or other searching that you can try, please indicate what is not covered and describe what it does and we will try to help you with a Firefox solution. Don't expect to see anything that is an exact replacement of a Google Toolbar feature. Likewise if you have additional solutions not covered others would likely want to hear about them.