Add-ons Manager won't open in Firefox 17? Here is the fix

Martin Brinkmann
Nov 21, 2012

Firefox 17.0 has been released yesterday by Mozilla and Firefox users have been updating their browsers ever since. Some may have noticed an assortment of odd problems in the browser after the update, among them that the Add-ons Manager won't open up anymore, or if it does, that no clicks are accepted on its page.

The issues are caused by the Tab Mix Plus add-on that adds a number of tab-related features to the Firefox web browser including options to duplicate tabs, control the tab focus, what mouse-clicks do and a lot of other things. The latest official version of Tab Mix Plus is not compatible with Firefox 17 at the time of writing. You can verify that by yourself by disabling or uninstalling the add-on in Firefox. If you can't access the add-ons manager, open your Firefox profile and move the add-on from the extensions directory to another folder to remove it temporarily from the browser. Make sure Firefox is closed during the operation.

To find the profile folder click on Firefox > Help > Troubleshooting Information and click on the Show Folder link next to Profile Folder here. You will also see a list of installed extensions here and their ID, which you may need to identify the proper file / folder that you need to move out of the extensions folder.

firefox troubleshooting information

When you start Firefox afterwards, you should notice that everything is back to normal.

You are probably asking yourself how to fix the issue. While you can leave the Tab Mix Plus disabled in the browser until a new version is released, some users may not want to use Firefox without the extension. A development version of the extension has been posted on the official support forum that resolves the issues that users experience after upgrading to Firefox 17.

Download the add-on from the forum - or more precise from Dropbox where it is hosted - and drag and drop it into the Firefox window once it has been downloaded. This installs the latest Tab Mix Plus version in the browser. Note that this version has not been verified or checked up by Mozilla yet.


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  1. Madeline Gleich said on December 9, 2012 at 1:27 am

    I have also used TMP for years and wouldn’t bother to use FF without it. However, the developer has always issued a “fix” on his own site before it can be approved by Google. It really is important that we support these developers. If their add-on is so central to your working comfort, as this is for many, then show him that. Even if you can’t contribute much, the act of contributing is an act of respect and appreciation.

    BUT I have a gripe with Google News, NOT Martin Brinkman, who does an excellent job of bringing important developments to our attention.

    Google News, which I use as my home page, has posted this issue about FF and Tab Mix Plus in a few languages, every single day since the new FF was released. For example, I have three tech news articles showing every day and they have always been about this relatively common and easily fixable problem with FF.

    Is there no other tech news of importance which, by now, should be taking the headline? Could it be that Google, who would like everyone to use Chrome (very faulty in its own ways), is continuing to make FF look bad by publishing the same material every day?

    BTW, I’m using FF 17.01 and Tab Mix Plus – use search to find it, or go to the developer’s site. There are NO problems.


  2. Ken Saunders said on November 23, 2012 at 3:56 am

    TMP is one that I’ve used for years.
    I’d hate to be without.

    If anyone is interesting in making a donation to the developer, you can do so at one of the following.

  3. Karl Gephart said on November 22, 2012 at 1:55 am

    Thanks for the fix, Martin! Works beautifully with TMP!

  4. Brian said on November 22, 2012 at 12:17 am

    Troubleshooting Information would not open ether, the link to the alpha version of the add on did help, so I;m good to go. Thanks for the help.

  5. JCS said on November 21, 2012 at 7:52 pm

    TMP had disabled my Firefox Help and Troubleshooting Information menu items as well, and those were also restored by installing the development version. Thanks!

  6. Peter said on November 21, 2012 at 7:40 pm

    I have Firefox 17.0, Tab Mix Plus, and All-in-One Sidebar 0.7.18 running in Windows. In All-in-One Sidebar’s Options > Panels > Add-ons > Behavior, I had configured add-ons to open in the sidebar, and I don’t seem to be having any problems with add-on management. Also, as other commenters have noted, manually navigating to about:addons seems to load Firefox’s Add-on Manager okay.

    However, since I updated to Firefox 17, doing a single left click on a link apparently generates three single clicks and opens three new, duplicate tabs for the link, two in background and the last one in foreground. The QuickDrag extension (which allows you to open links by dragging and dropping them) seems to be working normally, i.e., it is not opening duplicate tabs.

    NOTE: I just ran “Check for updates” in All-in-One Sidebar’s add-on panel and I see that Tab Mix Plus has been set (not by me) to be disabled the next time I restart Firefox, so I guess either Mozilla or the Tab Mix Plus developers have made an executive decision to disable TMP until its problems are fixed.

  7. Paul(us) said on November 21, 2012 at 7:37 pm

    Hallo Martin, First off all thanks again for yesterday’s help with fixing main tab mix plus problem. And also thanks for this really great article which If would have had yesterday I would not have to uninstall and install main browser to get ride of tab mix plus :-)

    But this article is so great because I belief when whit a newer version of Firefox I can happen that a same sort of problem will occur again, and than I can use this article to get ride of the problem.

    Am I correct can I use this fix (by going to Firefox > Help > Troubleshooting Information) to get ride of the new not working add-on in lets say Firefox 18?

  8. Ruben said on November 21, 2012 at 5:50 pm

    After updating to Firefox 17, I now cannot type anything on a dialog box, search box, or even into the web address box. I went back to Firefox 16 and everything is back to normal. I’m waiting for a fix before I try FF 17 again

  9. Bill said on November 21, 2012 at 5:26 pm

    Yeah, just put “about:addons” in the address bar.
    You can even bookmark it for quick access.

    It’s still not ideal, but less of a hardship than disabling TMP is you use lots of its features. I’m would imagine a fix is in the pipeline though.

  10. Jim said on November 21, 2012 at 4:41 pm

    I used TMP for years, but quit using it a year or so ago. I realized that most of the functionality I used from it had already been incorporated in the browser. The add on does a lot of things, but I didn’t use most of it.

    I try to keep my add ons limited to the ones I must have. They generally have a significant impact on browser performance and not in a good way.

  11. Daniel said on November 21, 2012 at 3:08 pm

    For some reason, this is a non-issue in Linux.

    But in Windows, i use Multiple Tab Handler as an alternative:

  12. Ray said on November 21, 2012 at 1:44 pm

    I can confirm that using the development version of TabMixPlus fixes the problems with the addons manager in FF17. Thanks for the info, Martin

  13. loen said on November 21, 2012 at 12:55 pm

    i dont even have tab mix plus, and im having troubles :(

  14. Bart Degryse said on November 21, 2012 at 10:35 am

    Or simply postpone upgrading to FF17

    1. JR said on November 21, 2012 at 4:07 pm



    2. Anonymous said on November 21, 2012 at 4:06 pm

      use about:addons

    3. Zlip said on November 21, 2012 at 12:24 pm

      I personally not suggested since FF17 is much snappier and contain several HTML5 new support and enhancement which can one user really enjoy.

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