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I installed Firefox 3 in my Mac yesterday and I'm liking it better than version 2. It seems to be faster and it solved some problems I was having.

So my day went along until I wanted to test a Flex app I am developing in Firefox (my default browser for these things is Safari). What do I see? Just the background. Nothing else. Not even right click > Movie not loaded message. No JavaScript errors... At first I thought Firefox 3 had broken SWFObject, or even SWFAddress.

I discovered later that one extension I have installed, Adblock, was blocking *ALL* Flash content. I was using SWFObject's dynamic embed mechanism, so I am not even sure how it was blocking that, but it was.

The solution: completely disable Adblock. By the way, you need to disable the extension, not Adblock's disable feature, because even when disabled, it wouldn't show Flash content. There are tons of comments describing this problem in the extension's page at Mozilla, so I hope they fix it soon.

So that's regarding Adblock. But I should also add to the title Firefox + Flex = disaster, because I am running into some very strange problems with the Flex app I was trying to test. I saw the problem on other apps as well. If I have some elements in the screen that are clickable, and I click on them, I would see the html background as a square in what it looks like the Flash player redraw regions, which are approximately the size of the element I was clicking on. That would make the square flicker for a second, then I would see the normal content. It's as if the redraw region would become transparent for a second, then back to normal. Very annoying. Normal buttons work fine. Has anyone seen this?




  1. Chris H

    Chris H

    hey laura,
    i had the same problem, even though it wasn't the firefox update, but the upgrade to flash player 10 beta.
    the problem i had was that some older versions of adblock don't automatically get updated (5.x). if you manually update to the most recent 7.x version, all should be well.
    if not, then i don't know what the problem could be ;D
    btw, nice work on the Mate framework! i'm starting to get into it and love it so far =D
  2. flobster
    stumbled upon this, so don't know if you are speaking of the same extension. I use Firefox 3 (Vista) with the extension Adblock Plus and there is absolutely no problem with flash content. By default it will show a transparent tab on each swf, so you can choose to block it.
  3. Wladimir Palant
    This is a known issue of the Flash plugin on Mac (at least if you use Adblock Plus). Switching off "Show tabs on Flash and Java" option fixes it.
  4. Laura
    I was using Flash Player 9.0.115. I'll check if I can upgrade Adblock and see any difference.
    I'm glad you like Mate!

    flobster and Wladimir,
    I was using Adblock, not Adblock Plus. I may try Adblock Plus instead.
  5. Brandon Ellis
    I had the same problem with Adblock on FF3 on the mac. Another big issue I've had is with the Bookmark Toolbar. If I close out my browser (but keep the process open), the next time I open FF my Live Bookmarks are gone from the toolbar. If I right-click the toolbar and choose 'Sort By Name' from the context menu it redraws the bookmarks. Also, my Live Bookmarks don't auto update. This version of FF has been very annoying. :(
  6. jacob
    I could never see the "Show tabs on Flash and Java". I don't think the mac has this option
    going to


    and setting


    to faslse worked for me
  7. Dan
    Thank God you wrote this. I couldn't figure out for the life of me why swfobject was broken. Thank You!
  8. Luis

    The second problem you mention it is a problem for FF3 MAC.
    I've been digging into this blink for the last two days always thinking that was a very specific bug in the SWFAdress but my surprise was when I create a project without using the SWFAddress and using only a couple of ExternalInterface calls.

    Here there is an example, the grey button on the left calls an alert with a timeout and there is not a problem, the second button calls an alert straight away and the whole movie goes 'bananas' and the red button on the right calls a simple scrollTo(0,150) using ExternalInterface.call and makes everything to dissapear apart of some graphics.

  9. Laura
    Hi Luis,
    yeah, the problem came down to SWFAddress. There were some people talking about in the forums. The only work around that somewhat worked was to add a delay.

    But now you are saying that the real problem is in ExternalInterface, which SWFAddress uses... I wonder whose bug this is, I really don't like the workaround.
  10. Darryl Jonckheere
    I am finding sites embedding Flash via SWFObject 2.0, when viewed in Firefox 3.0 with AD Block enabled, do not display. Disabling AD Block solves the problem however sites embedding Flash via SWFObject 1.0 with AD Block enabled (Firefox 3 again) do not suffer from this problem.
  11. Celilu
    SWF object in my site was broken too when i installed firefox 3. Its just a simply swf not an ad actually. :(
  12. Amit
    I had the same problem, and use the same solution.
    But after deleting few extensions more, FF works much better ;)

    Make sure to disable/delete unused extension for a better performance.
  13. flexsucks


    you must disable all addons in the browser you using for developing/testing except for the developer/bug management addons. That's natural. You must be a beginner to fail on this.

    Adblock blocking all **unsigned** swf objects? Maybe even signed ones? Oh, what can I say? That's why we love that addon: to get rid of all the crap :)
  14. Jason
    Adblock will block flash that it identifies as the same as another flash object that has been blocked. This means different things at different times but to the end user the result is often that they block a flash ad on one site, and find that flash videos stop working on another.

    The common example is that a user blocks "http://download.macromedia.com/pub/shockwave/cabs/flash/*" on one site after seeing an annoying ad and now any other flash that matches that address (which is very common) is now blocked for the user everywhere.

    Other than for videos, all applications of flash tend to be annoying for users as it is.
  15. Ian Ford
    I've had the same problem. I had problems with firefox's built in popup blocker as well. I wasn't able to add an app running off my local file system to the exclusion list. Big pain in the neck.