Firefox Support Forum

For the past few weeks I've been receiving numerous firefox crash reports & also when trying to open firefox an error indication that firefox is already open. I've never had this problem with firefox in the past, and have been an avid firefox user for many many years.

This occurred on my old desktop computer which died this week & is also occurring with my brand new, out of the box HP laptop computer (with ALL the windows updates and HP updates installed); The old computer used Windows 10 Pro, the new computer uses Windows 10 Home.

My old computer used just the windows defender for protection, but my new laptop comes with a 1 month trial of McAfee which I am using until the trial expires.

Firefox is (and was) my default web browser. The software and updates for firefox have always come from your official website and in a timely manner.

Could you please look into and resolve this issue?

Thanks so very much for being Mozilla Firefox!

I'm using 64-bit Linux Mint 20.3 LTS, and the latest version of Firefox from the repositories (101). Suddenly, for no reason I know, my default profile has started crashing immediately on trying to run Firefox. A small window comes up with the error message

XML Parsing Error: not well-formed Location: chrome://browser/content/browser.xhtml

     <button when-cofnection}"secure-cert-user-overridden"="" <="" pre="">
and then a line of ------^  where the ^ indicates between the t and the i of cofnection
Yes, I emphasise that I HAVE copied the error message carefully, including the mismatched bracket pair and the cofnection rather than (I assume) connection
I've managed to get a working version of Firefox by creating a new profile and using that (as in for posting this request for help), and I do have a recent backup of my bookmarks, but it will be a royal PITA if all my logins and passwords have disappeared. I don't want to go any further than this without some guidance, as all the messages I've found detailing how to fix this seem to make the assumption that I'm running Windows. 
Can anybody help, please?
</button>

I routinely record short screencasts with Kazam, and I can't watch my own videos after posting them on sites like GitHub because Firefox says "Video can't be played because the file is corrupt". Or for example when I upload them to sites like ezgif to convert them to a GIF, which works just fine because, well, the file is not corrupt. Other browsers like Chromium play them just fine.

Apparently the "OpenH264 Video Codec provided by Cisco Systems, Inc" is properly enabled in my system. This has been happening to me for months or years, but only today I decided to open a thread here.

There are two things here:

1. Firefox can't play the file. I'm sure there's some sort of misconfiguration on my side, or bad defaults, or a missing plugin, or similar. 2. Firefox shows a misleading message. The file is not corrupt! The root cause is something else.

Any advice on how to fix the first one?

Used Firefox for many years with the inbuilt Microsoft on screen keyboard without problem.

After updating Firefox a couple of days ago to the 100 edition when I enter text in Google and press enter Firefox instantly crashes.

If I use the touch screen keyboard in windows its fine.

Using windows 10 fully updated.

Any help appreciated.

Since the Firefox 99 update loading some pages (for example, the Gmail sign-in page) using Firefox on my Linux Mint machine, that I'm running a VNC remote desktop session on, results in a crash.

Crash report ID: bp-5dc1e89d-dc1f-40f2-9dbe-7f4380220419

I've tried running Firefox in safe-mode and the crash doesn't happen, but turning off hardware acceleration, swapping to default themes, removing all extensions, and completely removing Firefox and the .mozilla folder and then re-installing Firefox have not changed the crash behaviour in the absence of the safe-mode flag.

I would appreciate help in identifying what other paths of investigation I can take.

Hi, my Firefox on Win10 doesn't work, I've been forced to go back to Chrome. After a crash in Win10, Firefox doesn't work anymore: it opens, be it launched by me or by other programs, but it just sits there, blank, doing nothing. It is impossible to interact with menus and everything. Task Manager shows two open instances of the browser, using RAM, but the browser doesn't do anything. It doesn't "crash" and it doesn't freeze, it just stays like that. If I quit it and try opening it again the PC tells me it's open already, and Task Manager shows a couple instances staying there after quitting it, as if it stayed stuck. I tried resetting it from the Apps settings of Windows, but nothing happened, I tried uninstalling it and then installing it again, but nothing happened. Restarting the PC a couple of times changed nothing. In the end, I had to go back to Chrome and even put it as default browser because all programs were calling up Firefox which stayed unresponsive. Anybody knows what I should do in a case like this?

hey folks,

since today firefox wont load any websites out of troubleshoot mode. not even settings/ about:config. if i open a page in a new tab it just stays blank and nothing is happening.

in troubleshoot mode i turned off hardware acceleration - nothing changed after restart. i updated the runtime file "Visual Studio 2015, 2017, 2019, and 2022", which is suggested in different help-posts, i deactivated all addons, i created a new profile and also tried an imported one from eralier today - so far nothing has worked.

i also reinstalled firefox with version 99/ version 101 two times, after i cleared %APPDATA%-data.

im also just using windows defender as antivir.

please elp, i'm out of ideas.

I followed instruction several time to uninstall and reload fresh and Firefox will not run, except in safe mode. This issue has happened once before and I solved it by reloading it fresh but this time I cannot get it to run.

In Firefox, my instructor and student grade sheet no longer displays the horizontal scroll bar to bring more data extended off to the right of the page into view. I have an image attached where the scroll bar should be present. This begin in May sometime, and I'm not sure how to fix. I have tried re-installing fresh a few times, and removed any custom settings that might have been in place. Any and all help would be VERY appreciated as one of colleagues is super frustrated and I would love to find out an answer for both him and myself.

A couple users at our site intermittently receive a SSL_ERROR_BAD_MAC_ALERT error when navigating to Google in Firefox. This happens in Version 99.0.1 (64-bit) on Windows 10 computers. When the issue occurs, users can navigate to other websites without issues. Navigating to Google in a different browser works no problem. Restarting the browser will resolve the issue. Clearing cookies and site data has no effect. Users can also refresh the page after some time and the issue will go away.

Any idea as to why this is happening?

Upgraded to version 101.0 after getting the pop-up prompt and now every site I visit is taking at least twice as long to load and display compared to yesterday. (Even this support site!)

It has to be something in this release and not my connection, because:

• My mail client is completely unaffected and is behaving normally.
• I tried accessing the sites that were loading/displaying slowest using Opera, and they loaded as fast as they had in Firefox previously.
• Nothing else that uses my internet connection is working any differently than yesterday.

I also cleared the Firefox cache. No improvement.

It's not my add-ons because the only one I have installed is uBlock, which is recommended in various help articles here at the support site.

Nothing in the knowledge base has proven helpful.

Is anyone else having this problem? Is there some tweak I need to make in about:config to fix this? Or is this another case of "wait until the next release", yet again???

When I am typing an address or search term in the address bar, something happens to convert fl to "I. For example, as I type netflix.com, it ends up being net"Iix.com. The address still works (I end up on netlfix) but it looks like there is a bug in how the text is rendered in the address bar. I am on Firefox 100.0.2 on openSUSE Tumbleweed

Hey folks, hopefully you can help with this mysterious issue!

I've been running Firefox successfully on my Windows 10 PC for a long while now. Last night, for some reason it simply ceased to work. New windows and tabs would not load any content. I also couldn't access the Settings at all (clicking on Settings in the browser menu produces no results or feedback.)

Yesterday, I had Firefox open all day (I usually have my computer on all day), and it was working fine. Around 8 or 9pm, I first noticed that none of my open tabs were loading any content, and the tabs had the "loading" animation playing. New tabs would also not load any content. I assumed it was an internet issue as I did see my internet connection get disrupted once or twice. I did not see anything (apps, etc) on my PC updating.

This morning I found Firefox was still not loading anything, although my internet connection was fine. I tried opening Chrome, and it ran just fine. Everything else that it is internet or cloud based on my PC is running fine too. So it seems to be an issue just with Firefox.

I have listed my steps to troubleshoot below, but I want to note one weird thing I observed: Even when Firefox is closed, and Task Manager doesn't show any Firefox processes open, my PC seems to think Firefox is running. For ex. while trying to uninstall Firefox or delete certain files, I would get a warning to "close Firefox first" or "can't perform this action while app is running." After seeing these, I would again confirm that Firefox appears closed and Task Manager shows no related tasks.

My PC build: - Windows 10 Home, 64 bit - Version 20H2 at start of issue (updated to 21H2 during troubleshooting) - OS build: 19044.1526

Things I have tried for troubleshooting already: - I have WebRoot on my computer due to my job, and I asked our IT staff if they could see WebRoot blocking anything related to Firefox on their end. They said it was not. - Used "Firefox Refresh" - Uninstalled and reinstalled Firefox - Cleared app cache / app data - Updated Windows from 20H2 to 21H2

Note: This message was sent on a different computer & browser

I have Firefox 100.0.1 on my Mac desktop, and Firefox 100.0 on my MacBook Pro laptop. I can no longer access my Microsoft OneDrive account via the web on my desktop, but I still can do so on my laptop. I have gone through your posted troubleshooting steps for Firefox on my desktop, to no avail. How do I get my desktop back to version 100.0 so it will work again? I can access my OneDrive account via the web on my desktop when I use the Safari browser, so the issue is definitely with Firefox version 100.0.1, and not with my desktop.

Just paid $150.00 for a remote session from my computer store. Advice is: My older computer (2004)and it's graphic capabilities aren't compatible with newest FF. So I'll stick with older version (9) until I decide to get new computer. Firefox is my preference, but if I update, it's likely to break again. Please tell me how to stop all update notices. It is maddening. Or, if you can do it, please do. I don't want to use the others. It has crashed twice, just FF, in the last few days. A system restore saved me, but I updated and lost it. Can you help this not wealthy person? I thank you for your fine product, and your help.

I cannot watch a video on youtube when it is in the process of being live streamed. I remember a time when I was able to, years ago, but I can't any longer. I'm not sure what has changed. I found an article that says to install the optional update called "Windows Media Pack" in apps and features, but no app with that name exists. It was only a year old solution, so I'm unsure of what changed so significantly. I just installed another optional windows update, and also updated the browser, but still doesn't work.

Edition Windows 10 Home Version 21H2 Installed on ‎09-‎Jun-‎20 OS build 19044.1466 Experience Windows Feature Experience Pack 120.2212.3920.0

Firefox: 97.0 (64-bit)

I cannot open OneDrive with Firefox. I tested Safari and Chrome to see if they have the same problem. They both were able to open OneDrive. The only Firefox extensions I have are Adblocker Ultimate and Print Friendly & PDF.

I have an ASUSStore where firefox is managed by them and is at Firefox 95.0.0.r1 The localhost page shows Boxes with the unicode codes in them - Firefox on a PC to the IP address of the box works ok

I also found that some internet pages work (display english text) and some do not - I have logged a ticvket with ASUS but is anyone able to see an obvious difference between the following URLS These URLs were on the on the Firefox startup screen default webpage Note that Show source of all these pages only shows boxes with numbers in them as well so I can't clearly see on the ASUS what the difference is

The following did not work

   https://www.amazon.com?tag=admarketdeskt-22<tracking>...

but I tried https://www.amazon.com?tag=admarketdesk and this was fine - so then I refreshed the full URL with the tracking tokens - and it was working as well

The following do not work That is they display boxes with unicode values

   WikiPedia - https://www.wikipedia.com
   Facebook - displays boxes with unicode value https://www.facebook.com

The following work with proper english text

   FireFox Privacy - https://www.mozilla.org/en-US/privacy/firefox/
   Trivago - httpd://www.trivago.com?_wr=1&<lots of tracking parameters>
   YouTube - https://www.youtube.com

Hi - I'm currently working abroad as a photographer, and am having great difficulty uploading image files larger than about 25mb. Is there a Firefox limit on files larger than this, or is there a setting I can use to allow larger uploads? Thanks, Alex