Possible window load handler failures in Firefox 16

An add-on compatibility problem was recently discovered in Firefox 16. It is present in Firefox 16 and above, and we’re currently investigating it.

The problem is that the window load event handler that many add-ons depend on isn’t fired under some circumstances. So far it appears that this only happens when a popup window is opened, and only in cases where the domain in the new window is different from the one that opened the window. Since most add-on scripts rely on the load handler being called, many of them will not work in the newly opened popup window. There’s more information about this in bug 799348.

At the moment we consider the impact of this bug to be fairly minor, so it won’t be fixed until Firefox 17 unless there are sufficient reasons that merit the creation of a 16.0.1 update. If your add-on is affected by it, please let us know how in the comments.

31 comments on “Possible window load handler failures in Firefox 16”

  1. Jonathan Kamens wrote on

    Thunderbird too?

    1. Jorge Villalobos wrote on

      That would be much less likely, since this is triggered by popup windows that are opened from content.

  2. alice0775 wrote on

    Affected addons

  3. techno wrote on

    problem when we “view source” by right click.No window opens.

    This is for other item too.

  4. Ombligo wrote on

    Worst update I ever had.

    Can´t open any website

    Connecting …. (for hours)

    1. Jorge Villalobos wrote on

      Please report this on our support site.

  5. Ronan Jouchet wrote on

    Good to hear you’re aware of the problem 🙂

    Firebug is affected too:

  6. J wrote on

    Firebug has problems as well: https://code.google.com/p/fbug/issues/detail?id=5949

  7. Mylith wrote on

    Firebug is also affected. Yet another reason to downgrade to FX 15

    >Security Vulnerability in Firefox 16 https://blog.mozilla.org/security/2012/10/10/security-vulnerability-in-firefox-16/

  8. Martin Keckeis wrote on

    NO FIREBUG means NO FIREFOX for me anymore!

    Im switching to the more stable chrome -> sorry guys….

  9. gunnar wrote on

    context menu image saver also affected: https://addons.mozilla.org/en-US/firefox/addon/context-menu-image-saver/?src=search
    I had to downgrade to FF v15.

  10. kiki wrote on

    nothing for me is loading correctly. shows links but thats about it and sites such as facebook wont even load my feed it just keeps loading with nothing happening

  11. Pradeep wrote on

    After installing Firefox 16.0.1(update from firefox 15), there are issues with addons.When I install the Adblock (for example) addon, then it shows(at the botton -on addon bar) that adblock symbol, and it works on sites like http://www.youtube.com, kat.ph .. But, after I restart the firefox browser (close it and then start firefox ), the adblock doesn’t work… ( but it shows that it is installed .. in the addon page )… I have to reinstall it once again to make it working, even though I had installed it earlier…

    This doesn’t happen only with Adblock, but with other addons as well like …Goole Translator, Flash Video Downloader…etc.

    Hope the issue is fixed.. if its any issue, else, pls give a solution of it…


    1. Jorge Villalobos wrote on

      One way to resolve this problem is to install Firefox Beta from this page. The bug is fixed in that version.

  12. Brenda Franklin wrote on

    It happens when I am working in wordpress and click on View Page to check how the page looks in the browser. Very frustrating for a web developer!

    I am not at all happy with your saying that it won’t be fixed until Firefox 17.

    Unfortunately using a work around is too time consuming so if I can find an alternative in another browser I will do so unless a new version is brought out very soon.

    1. Jorge Villalobos wrote on

      What is the problem you’re experiencing?

      You can try to solve it by installing Firefox Beta.

  13. Jada wrote on

    I have this problem with almost every legitimate pop up that tries to open. I can’t even click on a picture to zoom in on such as an item on the Target or Home Depot website. It’s suck a nuisance that I end up using IE which I hate. Is more than a minor nuisance for my usage.

  14. Swapna wrote on

    We are having the same issue too. After upgrading to Firefox 16.0.2, there are issues with Javascript calls (Eg: window load handler). I have also Installed the Firefox beta (version 17) but the bug still appears here. So it does not look as if the fix has been done for the Beta version too.

    Can you let us know when this will be resolved.

    1. Jorge Villalobos wrote on

      Can you show me an example of this problem? If it is happening on 17, it sounds like a different situation.

  15. Mar Blanco wrote on

    After the latest update (16.0.2) nothing loads. No page at all. Not even no internet connection, just a blank page. Nothing loads even in “Safe Mode”. Looks as if it was pretty dead.. Even if I dissable all ad-ons. Nothing will load.

    1. Jorge Villalobos wrote on

      I’d recommend looking for help on our Support Site. I think you’re describing a different problem.

  16. Maria wrote on

    We have a number of firefox extensions. We keep track of versions in localStorage for each extension to determine if new installs. Around Oct 22 we saw an unusual spike in our numbers. It seems like the localStorage data for the extension got erased or could not read localStorage. We saw this once before this year in April coinciding with the Release of Firefox 12.

    Do you know anything about this?

    1. Jorge Villalobos wrote on

      I don’t quite understand what you mean. What does the extension store in localStorage? Is the problem that the localStorage is reset?

      1. Maria wrote on

        It stores a value in localStorage. The value may have gotten may have gotten reset or removed during the upgrade but I can’t say for sure. We use the same code to read and write to localStorage in all extensions we have for the other major browsers like Google Chrome, Safari and Opera and we have never encountered this problem.

        1. Jorge Villalobos wrote on

          Yeah, I’m not aware of any problems related to localStorage, but not many add-ons use it. Most use preferences or the separate Storage interfaces to do that.

          Let me know if it happens again, or you find steps to reproduce the problem.

  17. John Lee wrote on

    I am experiencing a similar problem with FF 16, but it’s got nothing to do with add-ons.
    My website is javascript based. A user can save either personal or social networking status information. Once the item is saved, the icon appears next to the date where it is tagged. Clicking the icon will normally show the summary of the saved item on the folder next to the calendar. However since FF 16 this is broken. I have tried disabling the new garbage collection features but no difference. The feature works well in FF 15, Chrome and Safari. I have not tried Windows version yet.

    1. Jorge Villalobos wrote on

      You should create a test case that demonstrates the problem and has as little code as possible. If you can post it here, I can give it a look.

  18. Linda Toews wrote on

    Since I downloaded the new 16.02 version I cannot get secondary pages of a website. It tries to upload a web page, but then it just goes to a white screen and nothing happens. For instance my online banking website (TD Canada Trust) – I login my info, etc. and it tries to go into the banking system, but a white page appears and it goes no further. I have contacted the bank directly and we have used Internet Explorer and it works properly, in about 4 seconds time. The bank has informed me this problem is Firefox, NOT the banking network. Recently, other secondary websites are doing the same thing. I have uninstalled the Firefox new version and will NOT upload a new one unless I know it is safe. Please inform me what is happing on your end.

  19. Rajeev K.R wrote on


    I have problem with flash player plugins. On my firefox flash objects are not working. It says missing plugins. Even if I install the flash player it installs. But when I open the browser again. It says Missing Plugins. Is anyone experiencing this problem?

    Also some of the dynamic fonts for the websites do not load properly.

  20. Kalman76 wrote on

    Seems that the same problem appeared again with FireFox 24

    1. Jorge Villalobos wrote on

      What problem are you seeing? With which add-on?