Sunday, August 21st 2011

Disable Compatibility Check in Firefox/Beta/Aurora/Nightly

After Firefox 4 was released, Mozilla switched to a so called rapid release cycle for Firefox. This was done in order to get new features out faster.

The idea in principle is great, but sadly this change was slightly rushed. For instance, the update mechanism wasn’t made completely invisible before starting with the rapid releases. This means that users are still getting dialog boxes thrown in their faces with every update, every six weeks. Compare this to Google Chrome which has updated completely silently from day 1, if I’m not mistaken.

For some reason Mozilla also still feel the need to show a first run page after each update, informing you about the update.

Extensions being automatically disabled with updates has been a long-standing problem with Firefox, and if anything it has gotten worse with the rapid release cycle. Ideally the user should never have a reason not to update to the latest and safest version, and this is a huge issue for many Firefox users.

To stop your extensions from being disabled you need to switch off Firefox’s extension compatibility check. The good news is that this is fairly simple. The bad news is that you have to redo this procedure with every new version of Firefox (i.e. every six weeks) until Mozilla work out a better solution.

Here’s what to do:

  1. Check which version of Firefox you have. Go to Help -> About Firefox and make a mental note of the version.
  2. In the location bar, type in about:config.
  3. If you get the prompt, promise to be careful.
  4. Right click in the list of settings and choose New -> Boolean.
  5. Name the new value extensions.checkCompatibility.X.X, where X.X is your Firefox version number.
  6. Choose False in the next dialog box.
  7. Restart Firefox for the change to take effect. Now you should be able to enable any extensions that had been disabled.

The above works for the update channels Release, Beta and Aurora. If you are on the Nightly update channel, you need to put in nightly instead of the version number X.X.

Now let’s hope that Mozilla get their act together and fix the current update mess and do something about the extension problem!

7 Responses to this post:

  1. Joden says:

    Thanks for your information. I’m tired to redo these every time.
    I have switched to Avant browser and will stay there until firefox go to the end of its rapid release circle.
    I love firefox , but the decisions form it these day are really disappointing.

  2. David Naylor says:

    I understand that you’re fed up. I’m sticking with Firefox because I believe in Mozilla’s mission, but I’m also getting really frustrated with the sub-par updating experience.

  3. David Jackson says:

    Just use the Nightly Tester Tools extension (available from the usual add on repository at Mozilla or from After installation and restart, force compatibility of addons with with 9.0a1 or earlier by selecting the menu item “Tools/Nightly Tester Tools/Force Addon Compatibility”.

    All addons will be activated, although some may not work in more advanced versions of Firefox. If they don’t work or cause problems, then disable the offending extensions.

  4. David Naylor says:

    That’s one way of doing it, but previously I’ve found that NTT itself also has been disabled by Firefox, so I’ve ended up having to go through the whole about:config routine anyway.

  5. Jed says:


    I’ve found setting “extensions.checkCompatibility” to false has worked for every major/minor release.

    It looks like the false value for every major/minor release has been auto-set for me


  6. Jed says:

    And weirdly, I can no longer enable compatbility checking.
    Either via the add-ons GUI, or via about:config!

    I try to set the value to “true” for all the 7.0 entries, & the generic entry.
    But most have returned to “false” after I restart the browser.


    Have remained “true”…
    But compatibility checking hasn’t been re-enabled as a result.

    Freaking bizzare….
    Do I get emailed if someone responds in this blog thread?

  7. Jed says:

    I just tried to enable it via the add-ons GUI…
    After I restarted the browser it was disabled again!

    The incompatible add-ons it disabled were re-enabled, so I needed to restart.

    After restarting we’re back to square one… so weird!