Firefox Community Forum

A recent set of system updates appears to have made most website videos not play in Firefox.

When I inspect the Developer Tools - > Console tab the most detail Firefox gives are an error line similar to: Media resource URL could not be decoded, error: Error Code: NS_ERROR_DOM_MEDIA_METADATA_ERR (0x806e0006)

Internet searches for the error name and error hex do not appear yield any applicable troubleshooting, nor any methods of collecting additional problem data.

How can I obtain more detail on where the error is happening and how Firefox might be interacting with other packages present on my system?

Arch Linux has some older ffmpeg-compat packages, but those don't appear to match any of the web results, in that they're even older versions of ffmpeg.

yay -Ss ffmpeg-compat aur/ffmpeg-compat-55 2.3.6-4 (+24 0.00)

   Compatibility package for ffmpeg to provide versions 55 of libavcodec, libavdevice and libavformat, not anymore provided by the ffmpeg package

aur/ffmpeg-compat-54 1.2.12-4 (+87 0.00)

   Compatibility package for ffmpeg to provide versions 54 of libavcodec, libavdevice and libavformat, not anymore provided by the ffmpeg package

This is a silly one, probably.

My refresh button has mysteriously disappeared from my browser toolbar. I can just use cmd+shift+r to refresh, but muscle memory keeps looking for the button on screen too, and it would be nice to have it back!

I opened up the customize options, thinking maybe I just removed it by accident, but refresh doesn't appear to be an option?

I also opened it up in troubleshoot mode to see if that would change anything. It did not :(

I also don't have any extensions that mess with the toolbar, so I don't think that would be an issue (and troubleshoot mode should have disabled extensions anyway I think.)

I recently updated to 126.0.1 - no idea if that has anything to do with it, but this did happen right after the update.

There are a couple more people on here with the same question, and they all had easy solutions. I'm hoping I'm just not seeing a setting somewhere.

Thanks!

Automatically hide taskbar in desktop mode => Enabled Firefox => Maximised When cursor is moved to outer edge of screen, taskbar should unhide (Expected behaviour) but in this case it remain hidden (Reality). Firefox along with all other spinoffs give same result. Chromium based browser works perfect, and taskbar automatically unhide itself.

As OLED screen have became common as monitor, Taskbar auto-hide is must. If this issue cann't be fixed I may have to change my primary browser which I used for almost 15 years.

Kindly, look into it. If Chromium can do it, why not Firefox.

I have a HUGE problem with Firefox memory usage. Some open instances of firefox are taking anywhere from 600mb to 2.8gb of memory. Since firefox opens MANY instances even with only ONE active window, this very quickly uses all available memory (4gb) causing a full laptop crash.

More concerning is that CLOSING the worst instance of memory usage STILL leaves the single open page/tab open, so what exactly was the memory eating instance actually doing ???

I have included a screengrab of the many remaining instances of firefox in windows task manager AFTER closing the main culprit.

I have also included a screengrab of all the adblockers I use which I believed would limit unnecessary memory usage, but does not seem to be effective.

Many Thanks

Hi, I've upgraded to Windows 11 today and couldn't open Firefox since. Things I've already tried:

• Reinstall Firefox and delete all old files (Appdata & Program files)
• sfc /scannow and DISM.exe /Online /Cleanup-image /Restorehealth
• Windows compatibilty mode
• Firefox Troubleshoot mode won't open either
• ipconfig /release & /flushdns & /renew
• netsh int ip reset & netsh winsock reset

When opening Firefox in any way, i get a white window/just the window border which immediatly closes. When trying to start troubleshoot mode, the small window has the same issue.

I also checked the crashlogs and none were generated. The Windows event-logger also has no entries.

BTW: Here is a video of whats happening: https://youtu.be/AJP4rqZFxlY

I have no idea what to do - send help please.

ATT.NET is blocking my access to ATT/Yahoo email from my ATT.net account using Firefox ''but not using Chrome?'' I have stopped all tracking and cookie blocking

"Something's gone wrong We may be having trouble with your connection. Connecting your device to Wi-Fi could help fix the issue or try again later. If you were using an app, close this page. Otherwise, start over."

I recently switched ISP and now when I try to google anything with firefox I keep getting this message appear:

"Our systems have detected unusual traffic from your computer network. This page checks to see if it's really you sending the requests, and not a robot."

It prompts me to click 'I am not a robot' then pick out which lights have cars etc in them. Worked fine before the ISP change. Some notes:

- This does not occur on Microsoft Edge or Chrome. - The only add on I have is Ublock but it still does this when I have that disabled. Plus I have Ublock on Edge and there are no issues.

If it's my IP address, then why does this ONLY appear when I use Firefox? Surely it would also appear when using google on any browser if my IP address was in question...

From what I am reading online, my only option is to either: - Use a different search engine ; or - Use a different browser.

I'm curious to hear other people's thoughts on this.

I view a lot of pdf documents via firefox, the light gray background makes my eyes and head hurt after prolonged usage. In the past I found a solution on this forum that advised to set pdfjs.viewerCssTheme to "2" in about:config. This set the background of pdf viewer to black/dark gray. This has worked for years until recently when the pdf viewer switched to light mode again (pic 1). I checked the about:config settings for pdfjs.viewerCssTheme but there appears to be no change. I tried restarting the browser, setting the theme to 0 and to 2 again, updating browser. Sadly the theme is still light gray. Is there a way to change it again? The desired outcome is in pic 2. I do NOT want to change the color of the pdf pages themselves.

When I'm in full screen mode, The Apple, "Firefox" "File" "Edit" "View" "History" "Bookmarks" "Tools" etc menu bar shows up at the top and won't disappear. On my iMac Pro, it doesn't show up. i.e. Off.

I can't figure out what is the setting to make sure it does not appear. I went digging everywhere and can't figure it out. If you could tell me what config, etc I'm missing I'd appreciate it.

Screen shot attached to show which menu bar I mean.

My firefox is up to date: 126.0 (64-bit)

I've just switched to firefox from brave, and theres no button on twitch to enable picture in picture. Using the keyboard shortcut (cmd+option+shift+]) works, but I'd much rather click something on the screen. On brave there used to be a picture in picture button alongside settings, theatre mode, and fullscreen buttons, but on firefox this has been replaced by a clip button. There's no option for it if I right click (this works on youtube), and no option in the address bar for either twitch or youtube. I've tried disabling all my extensions and lowering protections but nothing seems to work.

Hello all

There was a pop-up on my Mac'S Firefox asking if I allow Firefox access to my local network devices. I clicked on 'No' And obviously now I can't access for example my router's webpage or any other webpage fromo any devices on my local network. How I can switch it back? Internet access is working fine.

Many thanks, Bogdan

From the subject line - I keep getting this error when trying to use Firefox Sync on my Windows 10 desktop. Sync already works on Mac and Android, and I've already verified that I'm using my primary email to login.

Hi, not sure what I'm doing wrong, but my logins and passwords simply will not synch between devices. I principally use a desktop Win10 machine, and an iOS version of Firefox. Have double-checked settings on both devices, tried forcing a manual sync from each to the other, all to no avail. Any ideas on what I need to do differently? TIA.

Hello. I love the feature. I didn't know it was a new feature because I started using Firefox around April. I saved my group tabs, very happy about it. Then I close and save it, then I opened it again, it was great!

I am a student, I use my group tab to add the tabs that have the resources that I need to, and would also like to study for more knowledge and for my next school year.

There was no problem at that whole time. In April 21, there was no problem until April 22, 23 no problem. But I forgot my charger at that time, because I was at my mothers house. Then I wait for weeks for my charger to come back, about 2 weeks for my laptop to revive there in my grandparent's house.

When I got my charger, and opened firefox. Wait, but at first when I opened firefox, it showed me that there is a new update, an update about tab groups that I already now. I looked at my group tabs, and they are not there anymore.

What should I do to get them back.

I'm having a pretty frustrating developer experience using Firefox to help develop an app that uses Server Sent Events. Now, I'm not sure if I'm the one at fault or if it's something to do with Firefox itself (most likely I'm missing a config option somewhere).

Anways, the issue I'm having is that I cannot seem to be able to see Server Sent Events in the network tab of dev tools. This is specifically what I'm looking for: https://firefox-source-docs.mozilla.org/devtools-user/network_monitor/inspecting_server-sent_events/index.html

I'm testing this functionality by going to https://sse.dev/testpage.html, opening my network tab. I can see the connection to the SSE endpoint however, all I see is "No headers for this request" or "No response data for this request". I know it's getting the data through the event source because I can do stuff with the data. I've also tested this in Edge and everything appears in their network tab as expected which, makes me feel like this is more of a browser-specific issue. Again, I feel like it's me missing a config somewhere or having a privacy setting set which is somehow messing with the event stream.

Any help is appreciated... I guess I got to use Edge for the time being 🤮

Good day, everyone,

I've been using Firefox for several months since switching over when the migration to Manifest V3 in Chrome gained momentum. Initially, Firefox worked flawlessly, but over the past couple of months I've encountered a recurring issue where downloads often fail -- sometimes right at the start and other times midway through -- especially with larger files.

I've encountered this issue across multiple machines, and changing the destination drive where the files are saved hasn't made any difference. Interestingly, the same files download without any issues in Chrome, so I've ended up relying on Chrome exclusively for downloads.

Has anyone else experienced this issue?

Thanks in advance!

I always set Firefox to open the previous sessions tabs when starting. For some reason during the start up over the past several days Firefox opens to the home page only. I then have to search the history to find the closed tabs. Except for this problem, Firefox is working perfectly.

Does anyone have any suggestions as to why this is going wrong and a possible way to fix it?

I have a very good PC (5800X3D, 7900XT, 32GB DDR4 3600), but Firefox (either the normal, canary and nightly version) can't play smoothly any 4K video (like the Borderlands trailer: https://www.youtube.com/watch?v=lU_NKNZljoQ ). 1440 and lower resolutions are fine, as are 4K videos on Chrome and Edge. FWIW, my CPU during 4K playback is barely used (1-2%), and my GPU's video codec (VCE) is used by around a third. Disabling HW accel makes things better, as it still stutters but it's (barely) passable. I already tried creating a new profile, but still it's the same.