A little while ago Mozilla decided that it would be better to change the way users are able to force extensions to work with any version of the Firefox, and that change has taken effect in the latest Firefox 3.6 release. If you glance through your extension list you may have found that some of your add-ons are disabled regardless of whether you once set the about:config preference called extensions.checkCompatibility to false. Going forward that setting will no longer be used.

The new solution is simple, but rather annoying for testers like myself. Users that are testing out pre-release versions of Firefox will notice that they have to repeat these steps at each stage of the development process (alpha, beta, release, etc…).

  1. In the address bar type: about:config
    firefox about config.png
  2. Right click anywhere on the page and select New -> Boolean
    firefox new boolean.png
  3. The preference name you need to use depends on which version of Firefox you are running:
    Firefox 3.6: extensions.checkCompatibility.3.6
    Firefox 3.7 Alpha: extensions.checkCompatibility.3.7a
    firefox boolean name.png
  4. Choose a value of false to prevent the browser from checking whether the extensions you’re running are compatible with your version of Firefox.
    firefox boolean false.png

It’s kind of frustrating that there isn’t a universal setting for this, but it’s understandable. I’m sure some users enabled this setting at one point or another and forgot about it. Then every time they upgrade their browser that setting was carried forward, and eventually they could be running extensions that haven’t been updated in years and could possibly cause browser instability. Forcing you to update this value makes you more conscious about what incompatible add-ons you are running.

If this really gets to be a pain you always have the option of installing the Nightly Tester Tools extension that can take care of all this for you.