Skip navigation

Firefox 5 Crashes: What is Causing Them and How to Fix It

web browser articlesIf you are one of the thousands suffering constant crashes from the June update of Mozilla Firefox 5, realize you are not alone. Literally thousands have reported on Firefox 5 crashing across all platforms, including Windows and Mac.

UPDATE: The crashes were clearly not a result of problems with Firefox but with Adobe Flash. Crashes happened as a direct result of landing on a page created or featuring Flash elements. Adobe was not keeping up with Flash updates and releases, nor were users updating regularly. Firefox tried desperately to create work arounds for Flash crashes, but in the end, turning off Flash within the browser caused Firefox to stop crashing. You can click the “play flash” button on the boxes that represent Flash on websites if you need to see the Flash animation or design element – but honestly, other than videos, do you really need to? Flash is dead, folks. Quit designing with it and avoid web pages designed with Flash and browse happy.

Here are some examples, starting with the search results of Firefox crashes:

PC/Windows users aren’t the only ones suffering. So many Mac users have had issues with Firefox 5, Mozilla has announced an update “soon” for OS X 10.7 Lion which will be Firefox 5.0.1. Hopefully, the issues facing Firefox for all operating systems will be resolved in the same update.

Here’s the basics of what you need to know.

First, there is no one stop answer to Firefox 5 crashes. Switching to Google Chrome isn’t a solution either, though it is an option. Chrome has its own issues and limitations. For power users, bloggers, and surfers, there currently is no replacement that matches what the power, capability, and flexibility Firefox has to offer.

Second, you cannot just roll back or reinstall Firefox 4. Firefox 3.6 is the next oldest stable version. I explain why below.

What is Making Firefox 5 Crash?

Determining exactly what is causing Firefox to crash can be a bit of a Sherlock Holmes detective mission. It used to be more complex, requiring some digging into code and looking under the hood in places dark and confusing. Today, it is much easier.

It begins with getting Firefox working without crashing.

Restoring Firefox to Gather Information

If you are using a session saver or have the built-in one turned on, you should be able to restore your crashed sessions after using Safe Mode. If not, check your browser history to bring back visited pages.

With a Session Saver, you can choose which web pages you wish to open. If a specific page like Facebook is giving you grief, crashing when you load the page, then disable that page to see if that resolves the issue. You may have to experiment to find which page is causing the problem, if it is a specific page.

If you can’t even get Firefox to start, use the Safe Mode for Firefox.

If you cannot resolve the issue based upon the page you are visiting, the next step is to test your extensions/add-ons and plugins to determine if they need to be updated or are causing the Firefox crashes.

Check Plugins and Extension/Add-on Updates

Firefox 5 auto plugin and add-on testerYou can access your plugins and add-ons through the Firefox menu. A quick scan will alert you to items which need updating or that are no longer compatible with the version you are using.

If you are using a compatibility override add-on, consider turning it off and disabling all incompatible add-ons during the testing process as one of these might be the issue, no matter how innocuous it may appear.

Firefox makes the process of checking for updates even easier with their fairly new Firefox Web Browser — Plugin Check & Updates, a page with a utility built into it that tests your plugins and add-ons for you.

Update everything it recommends. It may require closing your browser to complete the updates.

Check Firefox Crash Reports

If this doesn’t resolve the crashing issues, check your Crash Reports. Type about:crashes into the address bar in Firefox.

When you type in about:crashes, Firefox automatically submits your reports for “priority processing.”

On the list of your most recent submitted crash reports, click each crash report link to read the report.

While it might look confusing, the things to pay attention to are:

  1. Details > Signature: What does it say? Does it mention a function, file, plugin or extension?
  2. Details > Crash Reason: While not always helpful, sometimes this line can provide more information.
  3. Details > Related Bugs (bottom of page): Read the notes and check links to more information on what bug or issue might be causing the conflict.
  4. Details > Crashing Thread (bottom of page): What module is being impacted? Is it associated with the core program, a plugin, or add-on/extension?
  5. Extensions Tab: Check for current status of Extensions/Add-ons.

    Firefox crash report, showing details of related bugs and discussions

  6. Comments Tab: Others reporting similar issues often have their comments listed here which could lead to some help or more information.

Look through several of the reports. You might see consistent problems being reported, and a solution or notes might be in the reports as well. These are also the reports requested by Firefox Support.

Click the Crash Data for Mozilla Firefox header to see an analytics report of Firefox crashes per 100 Active Daily Users and other data. The lines in the chart are color coded per version. Hover over your version to get more specific data. This helps you to know whether or not you are alone and have a fairly unique issue, or part of a trending issue.

Some helpful crash report links are:

Currently, Facebook and YouTube are the mostly candidates for crashing Firefox 5. Facebook comes in at 58,925 as the top site ranking and 36,415 as a top level domain, and thousands at various subdomains at Facebook such as Facebook apps. It also wins by URL, so something on Facebook is causing problems with Firefox.

Whether it is a Firefox or Facebook issue, I’m still digging, but the numbers are hard to ignore as they keep increasing, jumping by hundreds even as I write this article.

This is also a good example of why you should report such crashes to Mozilla using their automatic crash reporting tool.

How to Fix Firefox

There are a variety of choices you can make with the information you have.

If a plugin or extension/add-on is out of date, update it. Restart Firefox and it might solve your ills.

If there isn’t an update, look for an alternative. If an alternative isn’t available, contact the author’s page to find out what the delay is or if support has been discontinued. If they request donations, consider making one to encourage their ongoing support.

If the issue has information linked to a resolution, then follow those instructions.

Check the Firefox Support Forums carefully to see if others are reporting the same issues. While many people are just complaining and not giving specific information, there is often helpful tips that might lead to the answer. If you find the right answer, make sure you mark it as helpful so others will take note.

Some people get too frustrated and decide they want to roll back to a previous version. Usually that’s not a big deal, but in this case, take some care.

NOTE: Do not try to install Firefox 4. A serious security vulnerability may put your computer at risk. Firefox 3.6 is the most current stable past version of Firefox.

Firefox 5 was pushed out fairly quickly as it was found to be fairly stable and a security vulnerability with Firefox 4 has made that version too risky to continue using. The only older stable and secure version is Mozilla Firefox 3.6.

To reinstall Firefox 3.6:

  1. Backup and save all of your personal settings, profile, bookmarks, etc. so you can restore them in the new version.
  2. Download but do not install Mozilla Firefox 3.6 yet.
  3. Do a complete uninstall of the current version of Firefox.
  4. Reboot.
  5. Install Firefox 3.6.

You may have to disable and remove all your add-ons if they are still featured as they may not work with the older version. If you cannot find an older version on the Add-ons for Firefox list, check with the authors for older versions that will work with Firefox 3.6.

Do Not Give Up on Firefox

As I’ve reported many times, Firefox has had a rough two years when it comes to compatibility issues and crashing. This brave leader in web browsing that took on Microsoft’s Internet Explorer domination and now represents a whole global market share, and today takes on Google’s world domination with Chrome, is still a force to be reckoned with, so have faith and keep reporting and helping Firefox improve.

The policies and behavior that made it a welcome choice for power web users and bloggers continues to grow and thrive, meeting our demands and parting the Red Sea of innovation in an ever worrisome web with security and privacy battles ahead of us.

It’s easy to turn to Chrome or other choices. It takes work to continue to report an open source, community led project like Mozilla Firefox. Personally, I think the work is worth it.

During the crashes of Firefox 3, I put Google Chrome to the test. After eight months of use, Firefox 4 was released, bringing stability back to Firefox. I compared the speed at which I could create a blog post between the two.

The same article took me 45 minutes in Chrome and 15 minutes in Firefox. The add-ons for Firefox make the task of blogging so much faster, copying links and content and editing the entire process to final publishable copy. Greasemonkey Userscripts save me even more time. While there similar add-ons are slowly being ported over to Chrome, they aren’t ready for prime time. When time is money, Firefox wins in my business.

Today, as long as I stay away from Facebook and Facebook apps, Firefox 5 isn’t crashing. So I’m not giving up.

Hang in there. Mozilla is a fairly agile company supported by some die hard fans.

Feed on Lorelle on WordPress Subscribe Feedburner iconVia Feedburner Subscribe by Email

Copyright Lorelle VanFossen.


  1. Posted July 12, 2011 at 10:46 am | Permalink

    Lorelle… again, you raise the bar! Have been doing my nut about these crashes! Thanks so much! Peter (your Genealogy blogger mate)

    • Posted July 12, 2011 at 10:54 am | Permalink

      LOL! Hey, we seriously need to talk more genealogy here and there and everywhere.

      And thanks. We tend to forget that blogging wouldn’t work too well if it weren’t for the web browser. Actually, the web wouldn’t work too well, either. 😀 It’s the key tool I use to do my work. Without a well functioning browser, life is seriously miserable. 😀

  2. Posted July 12, 2011 at 3:02 pm | Permalink

    I think the solution is also to hang on in there – but really users should wait for the the first dot release before upgrading. Every software product gets a dot release right? as software bugs are just always going to happen. I think waiting for someone else to find the bugs is a better way to go.

    The other thing to be aware of is that Mozilla is upping its development cycle with versions 6 & 7 of Firefox due to be released by end of year, this is good and bad. The good bits are that we get a faster smarter browsing experience with hopefully better bells and whistles – the bad bits are that developers will have to upgrade their plugin code for compatibility.

    You will need to check the website of the developers of your “to die for” Firefox plugins to check for compatibility, or if you already took the plunge then check through the menu in Firefox Tools>>Addons>>Extensions to see which ones are not compatible.

    So throw caution to the wind and wait for 5.1 then 6.01 then 7.001, 🙂

    • Posted July 12, 2011 at 3:59 pm | Permalink

      I don’t subscribe to waiting for “first dot releases” any more, especially when they are mandatory security or big bug fixes. I’ve learned the hard way to embrace every release. Because one is buggy is not an excuse to wait if the rewards are worth it, and for security issues, they are worth it. Been there, done that, survived the worms. Will not repeat. 😀

      Yes, Mozilla is pushing the releases, and whether or not that’s a good thing will be something to see down the track. If they keep on this way, it’s going to be weird to announce Firefox 26 pretty soon. LOL!

      It’s good that you believe in hanging in there. Hopefully, the next release will be out soon, but in the meantime, now that I’ve applied the above fixes and relegated Facebook to Chrome, no more crashes. That ensures my “hanging in there.”

  3. senian
    Posted July 12, 2011 at 10:33 pm | Permalink

    After the Firefox updated itself to version 5, all was okay for a few hours, and then for no reason my old bookmarks were gone, my address line was empty of visited sites, and NOTHING helps, not even system restore or user change. What the hell happened?!
    I have never met such a problem in the other browsers I used like chrome,Avant browser.

    • Posted July 13, 2011 at 11:04 am | Permalink

      It is not surprising that you blame Firefox for this when there are a lot of reasons this could happen, and Firefox might not be the culprit. If you are running more than one browser, they will often tap into the profile, especially the bookmarks, of the other browsers. Something with that browser might have impacted your bookmarks. Or you may have done something that changed or cleared those files. Check your Mozilla/Firefox/Profiles directory to see if they are there. Make sure you are using a bookmark backup add-on or option or a service that syncs your bookmarks to an online service, which Firefox now offers up to a specific file size.

      A system restore would not have worked, and may cause even more problems. Changing users might have helped but that usually does little. I’m not the support team for Firefox, so I recommend you search the Firefox Support Forum to see if others are having problems. Good luck.

    • Posted July 13, 2011 at 12:52 pm | Permalink

      One other thing to consider. If you’re running the built in “Firefox Sync” which is well known to totally mess up your bookmarks, history and such on a frequent random basis, that might be the problem. It’s not so much a problem with the browser itself but more a problem with the “Firefox Sync” servers and (off site) databases. There have more than enough complaints about this problem since “Firefox Sync” went from being a plugin (where the same type of problems were being reported) to a built in function of Firefox.

      • Posted July 13, 2011 at 1:36 pm | Permalink

        I’ve not been able to run more than insignificant tests of the new Firefox Sync. It’s size limitations cut me out immediately. So I use other tools and manually save my bookmarks every month or so. I rarely use bookmarks any more, though. Interesting how our dependence on something we thought once was so valuable is now gone as it is faster to just search a second time.

  4. Swalayan
    Posted July 17, 2011 at 9:46 am | Permalink

    my firefox crashes cause of plug in container like yahoo messenger pingbox that spend memory

    • Posted July 17, 2011 at 4:31 pm | Permalink

      Well, the answer is clear on that one, either don’t use it or look for the update. 😀

    • swalayanmotor
      Posted July 18, 2011 at 3:15 am | Permalink

      Thanks Lorelle,
      it’s really work but now i can’t use flash in my firefox

      • Posted July 18, 2011 at 8:52 am | Permalink

        Use a Flash blocker Firefox add-on. Ensure Flash is updated to the latest version. Flash is being replaced by HTML5, and most of us are truly thrilled to see it go.

  5. Pam
    Posted July 17, 2011 at 10:37 am | Permalink

    I updated my plug ins but silver lite isn’t updating I think my computer doesn’t have enough to update so should I go back to Firefox 3 I should of checked my requirements first. But other than that everything is fine but I some how change my home page so what should it be. And if I don’t have enough requirement and silver… doesn’t update am I not secure? Security I need to know? and also I’m not that good on the computer

    • Posted July 17, 2011 at 4:13 pm | Permalink

      Silver Life? Not sure what that is. I think you mean Silverlight, the Microsoft video plugin. If it is, Microsoft has discontinued it for HTML5. Very few sites even use it any more. Mozilla Firefox 5 System Requirements are actually very small, so I can’t imagine anyone having a computer that can’t keep up. You set your “home page” if you use one through Options > General.

      As stated in the article, the only “secure” versions are Firefox 5 and 3.6. Those are your only two choices.

  6. broker
    Posted July 24, 2011 at 3:31 am | Permalink

    Firefox 5 kept freezing my whole system. Now I have checked Addons and plugins and found an old version of Java Runtime in there! Disabled it and hoping for the freezes to stop, thank you for hinting at plugins.

  7. Posted July 25, 2011 at 7:31 am | Permalink

    I’ve been having problems, too. But this helped: FYI.

  8. Tan Bulut
    Posted September 30, 2011 at 8:08 am | Permalink

    Very helpful info, thanks. Being a mac user, I’m alsoo suffering from firefox crashes lately, yet I don’t want to switch to another browser, I think following your directions may help. Probably it’s related to some extension in my case, just need to find out which one.

    • Posted September 30, 2011 at 4:19 pm | Permalink

      The odds are that it is Shockwave Flash that is causing the problem. Skype is another bugger. Uninstall the Skype toolbar and add Block Flash extension so you can click on Flash to make it play and not have it crash everything. Firefox 7, which was released a few days ago, is MUCH improved in all of this.

  9. Chris
    Posted September 30, 2011 at 8:18 pm | Permalink

    Glad I found your post. Firefox has been freezing my screens and crashing daily. Now I know I am not alone. I am not that tech savvy so your suggested fixes made my head spin, lol!

    I don’t go facebook and youtube, so it must be something else. I’ve just uninstalled some obsolete plugins and hopefully it will work. If all things fail, I will follow your link to reinstall firefox 3.6.

    Will check back this thread often to see if things get better. I love firefox too much… and like you I’m not giving up 🙂

    • Posted October 2, 2011 at 9:53 am | Permalink

      Flash is everywhere. Firefox has upgraded twice since this article was written. I recommend you try Firefox 7 and ensure Adobe Flash is upgraded to the latest version.

  10. cbrace
    Posted November 23, 2011 at 5:36 am | Permalink

    I received a message to install a vital security update on firefox and 5 minutes later I only got crash messages and couldn’t get back on at all. I took your advice and removed it and then installed 3.6 version and so far all is well. Thank you for the help.

  11. pedropt
    Posted August 22, 2015 at 8:03 pm | Permalink

    Best way to solve your crash on mozilla (firefox) every time you open facebook is following these steps :
    -Uninstall mozilla
    -Delete every folder on your computer with the name (Mozilla)
    This last step will delete all your bookmarks you have in firefox and your stored passwords .
    These folders are under these directories :
    \Documents and Settings\Administrator\application data\Mozilla
    \Documents and Settings\Administrator\Local Settings\Application Data\Mozilla

    And do this to all other users on that computer .

    – Use CCleaner to clean up the temp files and to fix registry entries
    -Download latest version of Firefox and install it

    Notes : There are utilities on the net that can extract your passwords from mozilla and save them to a text file on your computer .
    There is also utilities to backup your bookmarks of mozilla .
    If you use any of these utilities , then make sure you use them before you delete your mozilla folders from your computer or even uninstall mozilla .

    After all these procedures everything will work right .
    I had that problem on one computer i have but i dont use it , and i realize that the problem for that to happen could be related to installation of scripts or plugins without user consent (spyware) , that people may get on facebook news or any other website .

    about:config in mozilla and resetting all the settings will not work , also , uninstalling mozilla and reinstalling it will also not work .
    you have to delete those folders by hand .

    • Posted October 10, 2015 at 9:26 am | Permalink

      This is a very old post, and yes, this is one way to resolve the issue, if you are tech savvy. Luckily, Firefox has improved its stability greatly, though it still has memory leak problems typically associated will malformed and deprecated site designs such as the use of Adobe Flash. Still, it’s one of the most powerful, flexible, and stable browsers out there. Thanks.

      • pedropt
        Posted October 11, 2015 at 2:09 am | Permalink

        I have wrote that solution to the latest version of Firefox in 2015 and not to version 5 .
        Firefox is only stable if you disable all your plugins on it , and if you have caution navigating on the web .

        And by the way , firefox does not respect your privacy by the fact that every website you type is stored on multiple could servers with your ip .
        anonymity on the web can only be achieved with one bowser that i have tested , it is midori . But also Midori have some limitations .

4 Trackbacks/Pingbacks

  1. […] Firefox 5 Crashes: What is Causing Them and How to Fix It ( […]

  2. […] VanFossen shared Firefox 5 Crashes: What is Causing Them and How to Fix It. Firefox 5 Crashes: What is Causing Them and How to Fix […]

  3. […] suffered greatly in 2010 from problems with Adobe Flash causing the browser to crash multiple times a day. It inspired them to create powerful prevention and protection systems to stop […]

  4. […] out at rocket speed to not just keep up with the browser market but to also push out fixes to those memory leaks and crashing issues that plagued Firefox 4 and 5 in 2010-2011. While Adobe Flash was the biggest culprit, Firefox had its own issues, […]

Post a Comment

Required fields are marked *

%d bloggers like this: