How-To Geek

Firefox 3.6 Release Candidate Available, Here’s How to Fix Your Incompatible Extensions

image The release candidate of Firefox 3.6 is finally out, but if you install it, any extension that still hasn’t been updated to support the latest release is going to error out or just not work.

What you’ll need to do is use the new compatibility hack to get it working. And before you start talking about nightly tester tools and other extensions to force compatibility, some of us don’t want to bloat up Firefox with yet another extension, and prefer the about:config hack instead.

How To Force Extension Compatibility with Firefox 3.6+

You can click the link to read the full description, or just create a new boolean key with this name, and value set to false:



The new version of Firefox adds a bunch of features like Personas themes that can switch without restarting the browser, notifications for ancient, insecure versions of Flash, and a bunch of extra stuff that will speed up the browser.

Download Firefox 3.6 Release Candidate 1 from

Lowell Heddings, better known online as the How-To Geek, spends all his free time bringing you fresh geekery on a daily basis. You can follow him on if you'd like.

  • Published 01/9/10

Comments (12)

  1. Haresh

    Firefox 3.6 RC? :O

    Firefox 3.7 is out too. Right?

  2. Kamlesh

    Haresh, at first look, I too had similar opinion. But if you notice Help->About, its final 3.5.7 which is available now :) And Mr.HotToGeek is talking about next version 3.6.

  3. Jaimin Rajani

    After doing this, my navigation/address bar disappeared. How do I get it back?! or fix this or delete the boolean key. The address bar visibility is enabled, still it’s not showing. Aaarrgh :@ ??? Please help.

  4. The Geek


    It’s very likely an incompatible extension. Try disabling the ones that aren’t compatible.

  5. Dwight Stegall

    Nightly Tester Tools is the only way to fly. It also allows me to add text to the titlebar so I can include insults about Google Chrome and other inferior browsers. :)

  6. Robert Claypool

    I use the latest nightly, and I’ve been forcing compatibility by saving the extension, opening it with 7-zip, copying out install.rdf, going to the section and at maxVersion changing the 3 into a 5, and then copying it back into the extension and dragging the extention back over the browser.

  7. pavid

    It’s much easier to go this route: Tools -> Addons -> Tools -> Make all Compatible then reload Firefox and voila all extensions are now compatible.

  8. The_Digitizor

    Doesn’t work for the Firebug extension. The firebug extion gets installed and after the restart I cannot see it nowhere. Any one facing similar problems?

  9. Bf

    There is very simple solution for this problem provided by Firefox team themselves. It is called “Add-on Compatibility Reporter” extension. It enables all previously incompatible extensions and provides way to report ones that do not function properly.

  10. eidylon

    cool – works great; still shows the icon with the exclamation mark showing it’s incompatible, but i guess that’s good. Thanks!

  11. Shahar

    Fantastic!! This is great, I almost thought I’ve lost that extension forever…

  12. noprob

    @ Robert Claypool

    Thank You very much for your explanation of forcing an extension to work.

    I have been using 7zip since way back in the win98se times so this was a breeze to do and it works!


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