All Products Support Forum

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?

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?
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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!

The videos look blurry and it seems like a little zoom part can be seen from one corner of the video to zoom in more. The whole video is not controlled within the skin. Nothing in the video can be seen after playing the video due to problems. I have started the application by deleting it several times in a row. In the first case it stays good for a few days and then it causes problems in video play. After browsing all kinds of websites, the videos get blurry. Hopefully that will solve the problem.

For several days I get the message "Login to server imap.gmail.com with username alansharp26@gmail.com failed". This seems to be since the following update has been installed: Thunderbird 90.10.0 (20220525135609)iNSTALLED 6 June 2022 , 22..22.43. I can receive emails using Outlook on my laptop, and also on my phone and iPad. I have checked the settings and they seem correct.

I’m having trouble sending mail with my gmail account. Have tried authenticating with Oauth2 but does not seem to work. Incoming mail works fine. Have tried rearranging settings but nothing works. Any help would be appreciated.

My phone is Nokia X100 with android 11. CPU is 480 5G UFS 2.1 storage Ram is 6gb I already did some tweaks in about:config but it is still slow to load webpages especially going from one site to another site. Any flags recommended? I know there is the option to reduce animations but they split into many animations flags I just don't know which are supposed to be able to speed up the speed by disabling them. Please share your view

Whenever I attempt to access DRM content such as netflix or spotify I am notified that the WidevineCdm plugin has crashed. I'm running firefox version 101.0.1 on Kubuntu 22.04, I am running the debian package release, but I had this issue with the snap version too. I've submitted crash reports, but they're all "EMPTY: no crashing thread" (https://crash-stats.mozilla.org/report/index/20af09a5-6bc4-4719-9242-38f5c0220614 here's one).

My email housekeeping is atrocious, and as a result, I have stored loads of emails with large attachments. As my inbox capacity fell, I learned to detach files and store them separately, but that doesn't solve the historic issue and I am at 95% capacity again. So I need a simple way of identifying the emails with the largest attachments (>5MB) without searching all my folders one by one. Any suggestions welcome!

When I look up the error message I get, everyone I see who got it can't open Firefox, but I can open it fine. For me, I have Firefox as my default browser and when another program (tModLoader on Steam) tries to open it, it gives me "Profile Missing," "Your Firefox profile cannot be loaded. It may be missing or inaccessible." I don't know if it gives the same error for other programs because I can't think of any programs that open my default browser. When I switch my default browser to Edge, the program can open Edge fine.

Win7 AMD quad core 64 bit desktop. A few days ago, Tbird 91.10.0 started failing login to both my gmail accounts; wouldn't download mail. When I checked account settings, the 'oath2' parameter had been changed. I re-selected 'oath2', and re-entered my passwords, and everything worked (getting and sending email, both accounts). Last night, when I tried to *send* an email, I got an 'enter password' popup. Entering the password (same one that worked to get mail) did not work, for either account. Today, the problem persists after rebooting, etc.

Gmail's web interface allows logins, receiving and sending mail for both accounts on the same computer.

The seemingly most applicable (closed) thread says to, among other things, enable cookies, but gives no direction as to where that setting is located.

Any thoughts on cause or cure? As I said, this failure just started 'out of the blue' a few days ago. I've used Tbird for many years without any of these issues.

Thanks for any assistance, Charlie

I'M trying to open Realtor.com and I get this message: Application error: a client-side exception has occurred (see the browser console for more information). Can't seem to fix it. Can you help?

Outgoing mail stalls. The blue line goes across from left to far right and then stops. A "message sent" does not appear. I have waited for 30 minutes and the stall persists, even with a short test message. I turned off my antivirus (Bitdefender) and firewall. Incoming mail is fine.

I have another computer that works well for both in and out mail. Both computers use the same ISP (Netfirms) and have identical outgoing server settings, except for the email address.

Your help is greatly appreciated!

James Meyer [removed email from public]

I'm not sure if this is the cause but a few days after windows update my firefox crashes. I restart it and only screen opens and doesn't respond. Deleted Firefox, did fresh install. Firefox starts again but as soon as I log in my account, crashes again. Delete firefox and again fresh install. I don't login, I save 3 bookmarks and it crashes again. Delete firefox again and fresh install. But now firefox starts in the background (seen in task manager) but does not open a window. Download latest installer and try to install but now install says, "something went wrong" during the download. (could be the enterprise network here) this I tried a few times but no success.

So I download Firefox 101.0.1 ISO and install. But again running in background and no window.

HP Elitebook AMD Ryzen 7 PRO 2700 Vega Mobile Gfx

64bit Win 10 Pro 21H2 - 19044.1766

Firefox 101.0.1 + extensions, Windows 11 22H2; both fully updated

Firefox has stopped saving the position of its window, looking to me like it is leaving space for my Windows taskbar but which is hidden.

Some online searching and I found that setting privacy.resistFingerprinting to false resolves the issue, but it is not a change I feel comfortable with and wonder if there is another solution. I have uBlock Origin installed so maybe I shouldn't be concerned.