Add-on Compatibility for Firefox 22

Firefox 22 will be released on June 25th. Here’s the list of changes that went into this version that can affect add-on compatibility. There is more information available in Firefox 22 for Developers, so you should read that too.

Update: please read this update for one more compatibility issue that was just discovered.



There is much more Places code cleanup happening in 22, so that file system access happens asynchronously. Read the documentation of Places utilities for alternatives of these functions and objects.



Please let me know in the comments if there’s anything missing or incorrect on these lists. If your add-on breaks on Firefox 22, I’d like to know.

The automatic compatibility validation and upgrade for add-ons on AMO will happen soon, so check your email if you have an add-on listed on our site.

41 comments on “Add-on Compatibility for Firefox 22”

  1. Kohei Yoshino wrote on

    > attributes and hasAttributes are now members of Element, instead of Node.

    Node.hasAttributes is still available. (Bug 849661)

    1. Jorge Villalobos wrote on


  2. Kohei Yoshino wrote on

    And this article has been published on June 3rd, not May 3rd.

    1. Jorge Villalobos wrote on

      Hmm, must be a WP bug, since I started editing the document last week. Thank you for pointing it out.

  3. Paulo Valentim wrote on

    I’m not much of a programmer.. Just sad that firefox 22 will break most good features I liked in my favorite add on:
    I guess I will not be updating when it comes.

    Just my 2 cents
    – Paulo

  4. Neal wrote on

    Firefox 22 is breaking a lot of functionality especially favicons sync with xmarks.

  5. Luke wrote on

    What about the major changes in Firefox Developer Tools? No more right click menu on the inspector’s css rules, stack trace has been moved to the top, probably other under-the-hood changes that could break addons that hook into it.

    1. Jorge Villalobos wrote on

      Those changes are unlikely to break add-ons. If you know of any affected cases, please let us know.

      1. madrum wrote on

        Since V.22 update – Problem of ‘Object moved here’ when navigating on various sites that I used.

        Resolved by disabling ‘Safelinking add-on’

        Will go back to version 21 when I have the time.

        1. Jorge Villalobos wrote on

          What do you mean by “Object moved here”? Can you describe the problem?

          1. Xiong wrote on


            I have been experiencing the same issue. I will be on one webpage, and then I click a button or link, and when the page loads, the only text I see is “Object Moved This document may be found here.” The word, “here” is a hyperlink. When I click on it, I then get redirected to the page I think I was intended to go.

  6. hanyu wrote on

    How about the NPAPI plugin?


    Version is a property of NPAPI plugin. But in Firefox 22, it errors to get ‘Version’ from:


    Is there some changes about it?

    1. Jorge Villalobos wrote on

      I haven’t heard about any changes in this. However, it sounds more like a web compatibility issue than an add-on compatibility issue. Try asking here.

      1. hanyu wrote on


  7. Evan Edwards wrote on

    Firefox 22 definitely broke the add-on “Tab Utilities”.

    Each new whole-number version seems to break that one.
    Unfortunately, it’s one I can’t live without. I’ve directly downgraded to 21.0 without un-installing anything, and that did seem to do the trick.

    Unfortunately, every time a major version comes out, I experience a few broken add-ons, and with the rapid-release program it has become such a pain that I’m officially finished with upgrading Firefox; I intend to stay with 21.0 while I look for a browser that can offer reliable, working add-ons. It’s just out of hand in Mozillaland.

    1. tab_util_user wrote on

      I totally agree. It’s really disappointing!

    2. Robert wrote on

      Looks like it’s time to move to Chrome.

    3. Patrick wrote on

      Agree. Rapid releases breaking essential addons, like tab utilities. Sad.
      I wish there was a “revert” button on the Check for Update screen that would take you back to the previous version of FFox.

  8. Alex wrote on

    Hello Jorge,

    Our company develops a remote desktop service. Everything was ok until Firefox 22 – it is hanging when trying to run our NPAPI plugin. You can try the plugin at
    Can you help with this? Where should we see? Thanks!

    1. Jorge Villalobos wrote on

      I’m not aware of any major changes in the plugins platform in Firefox 22. You can try asking in the tech.plugins newsgroup. That’s probably the best place to find technical assistance for plugins.

  9. Rob Robinson wrote on

    We also had a problem with out NPAPI plugin not working in Firefox 22. Turns out we had an attribute (hidden=”true”) on the embed tag for our plugin. Removing this attribute allowed Firefox to recognize the plugin again.

    1. Alberto López wrote on

      Same problem here.
      I have solved it removing “hidden=true” and using “style=visibility:hidden”.

      1. Thirilog wrote on

        Thank you!
        You saved my life!!

    2. Ioan-Cosmin Szanto wrote on

      This also happens with our NPAPI plugin and with the VLC plugin,

  10. Steve Tapp wrote on

    It looks like the Citrix client is broken again but in a different way than V21. Options? Our campus must have this working…

    1. Jorge Villalobos wrote on

      Have you contacted Citrix about this?

  11. Charlie Howard wrote on

    Our “foofaid.xpi” addon stopped working with FF22 but still works with FF21. This website only is used by a handful of people who are preparing books for Project Gutenberg, so in the grand scheme of things, this is of no importance. But it will impact our productivity, so some of us will have to stay with FF21.

    Nothing in the FF changelog seems obviously relevant to our implementation.

    1. Jorge Villalobos wrote on

      Are you the developer? How did it stop working, do you see any errors in the Error Console?

  12. Martin wrote on

    You mention that there will be an automatic compatibility validation carried out on all add-ons listed on your website. My company developed an add-on that is not published, thus only used internally. Is there a way to run this automatic compatibility validation on non-published add-ons too?

    Actually with version 22 this add-on stopped working and I am wondering whether this compatibility validation could give more information about the reasons.

    1. Jorge Villalobos wrote on

      We can’t run this validation for external add-ons, but you can run your files through the standalone validator: You can also get the sources from Github and run it from the command line.

  13. Nikhil wrote on

    Hi Jorge Villalobos
    My plugin was working fine till firefox 22.
    It is currently giving error
    Components.classes[cid] is undefined..

  14. Tim Robinson wrote on

    I also have a plugin that uses NPAPI. It worked fine on firefox 21 but doesn’t work on 22. Haven’t got to the bottom of it yet.

    I’m getting increasingly frustrated at the lack of change control being exercised by the Firefox developers – our IE plugin has worked for over 6 years without being even recompiled and the chrome one has worked just about unchanged too, but with firefox it seems every version has more breaking changes 🙁

  15. jonathan wrote on

    FF 22 is not compatible with the latest version of Quicktime. In order to restore sound from QT files, we have to use a legacy version, 21 or earlier. We’ve tried several suggestions posted on the following forum, all unsuccessful.

  16. Ray wrote on

    Looks like Camelizer is broken with Firefox 22.0.

  17. tony 123 wrote on

    Downloadhelper 4.9.15 won’t work with Firefox22 – I get a greyed out icon but doesn’t work when on youtube or other sites..It worked perfectly in the previous version.
    Can anyone help many thanks

  18. tony 123 wrote on

    It has now began to work normally !! Let’s help the problem its cured and will work correctly all the while.

  19. Sunil wrote on

    Hi Jorge Villalobos,
    I have downloaded the latest gecko-sdk for firefox 22
    But it is missing xpidl.exe file which should be in “bin” directory.
    Thats why Im unable to build my code with latest gecko-sdk.
    Please help me with this.

    1. Jorge Villalobos wrote on

      There should be an equivalent python file that you can use to build the XPTs. Alternatively you can use the exe of a previous SDK.

  20. Shalini Kuruvath wrote on

    Selenium ide is not compatible with firefox 23.0.1.

    I am not able to see selenium ide option in the menu even after installing Selenium Expert (Selenium IDE) 0.25 .

    Please look into this.

  21. James Edwards wrote on

    Now that nsIGlobalHistory2::addURI is no longer available, how do you add a URL to the history?

    The validator simply says “see mozIAsyncHistory for alternative functions”, however that interface doesn’t have a comparable function — updatePlaces only works for URLs which are bookmarked or have already been visited.

    1. Jorge Villalobos wrote on

      Do you get an error if you try to add a URL that isn’t in the history already? There must be a way to add new entries, since Firefox code uses the same interfaces.