Diễn đàn hỗ trợ Firefox

Hello,

I recently updated my Firefox browser to the latest version, 138.0.1 (64-bit), on Windows.

After the update, I noticed that when playing videos in fullscreen mode (for example, on YouTube or other video websites), the Windows taskbar (the bar at the bottom of the screen with the Start menu icon) does not hide automatically. This is affecting my fullscreen viewing experience.

Before updating to version 138.0.1, the Windows taskbar would hide correctly when entering fullscreen video.

I was wondering if anyone else has encountered a similar issue with the Windows taskbar not hiding, or if there are any suggested solutions to help resolve this problem.

Thank you for your help!

I've freshly reinstalled Windows 11 and after trying to access and watch a movie on any of these sites I get an error (see the pictures).

Browser version: 137.0.1 (64 bit) Widevine version: 4.10.2891.0

Already tried to disable/enable DRM. Already reinstalled firefox. Already manually installed widevine. No clue what could be causing this issue.

I have Win 11 dell computer that does not play or pick up sound from web sites videos .I checked and tested my sound using the Microsoft platform & buy playing a disc. It works OK

So, my problem is with HW acceleration in FF. Basically:

If its enabled: It causes graphical artifacts in videos [See screenshot]. If its disabled: It brings screen tear in to videos and autoscroll [Like if Vsync is disabled in games].

I tried safe mode, I tried reinstall of FF, I tried disabling and enabling extensions. I tried to set Vsync on in Nvidia control panel... the only thing that impact those bugs is HW acceleration in FF.

My drivers are up to date, my browser is up to date, yet there is such trouble.

Any ideas or solutions?

Hi,

How can I force Nightly to play a media type ? Per instance, the top main video here : https://www.lapresse.ca/international/asie-et-oceanie/2025-12-23/coree-du-nord/kim-jong-un-inaugure-un-complexe-hotelier-dans-une-station-de-montagne.php

Best regards iBenny

I get a "Sorry, the video player failed to load.(Error Code: 104153)" error when clicking links from a search for a video, if that video is available on YouTube it opens and plays just fine, not from other websites though - and it should. Fix?

This issue just appeared. Video will not play in Firefox. Windows10 PC, up to date with latest versions, as is Firefox. There is no error message or code. Just the spinning wheel. I see other people are having the same issue but I haven't seen a solution. Any ideas or help appreciated.

Hallo everyone,

after many hours of Google search and trying many changes in the "about:config" section im done with things to try so my last chance is here.

The problem i have is that videos dont play if i mouseover the firefox window or tab i.E. on the windows taskbar. The video will only start to play if i click on the window/tab and that window/tab is the "active" one im looking at.

It worked fine before but some firefox update f***ed this up (and yes the official firefox updates are the only thing that changed), no i dont know which update it was because i didnt recognize the problem right away.

The autoplay option is set to allow media and audio.

The weird thing is that when i open a video in the vlc player and do the mouseover, everything works just fine. So my conclusion is that some setting was messed up on the new firefox version.

Some data of my pc, everything is updated: - Windows 11 Pro - CPU is AMD Ryzen 7 5800X3D 3,4GHz - GPU is AMD Radeon RX 7900XT - RAM is 32GB DDR4 CL16 - Internet is wired connection with 250K speed - Firefox Version is 137.0.1

Sorry for my bad english and thank you in advance.

Windows just had an update, in that when I did it now Firefox has no sound at all in Youtube, Disney plus or any other site.

Now I did my own trouble shooting, games have sounds, my music player (winamp) has sound, I downloaded chrome and I oped volume mixer and played a video in that, there was sound.

I do the same thing in firefox and there is no sound, and in volume mixer where the lines go up showing the volume as it plays, it did it for chrome but not Firefox.

So there is no issue with my head set, my computer or my sound, it is firefox alone.

What the title says. Firefox just isn't playing any sound whatsoever.

Troubleshooting:

• Volume mixer indicates that Firefox is using my speakers, along with all other apps. When playing a YouTube video, the green bar is not bouncing. However, all other programs that play sound do so successfully and their green bars are bouncing (see attachment).

• Other web browsers play sound successfully.

• Restarting Firefox and my computer did not help.

• Switching the default sound device and changing back did not help.

• Changing to headphones made no change.

• Tabs are not muted.

• Autoplay settings in about:preferences showed that audio and video were disabled, however changing this setting to allow video and audio, then restarting both Firefox and the computer did not fix the problem. I have no idea how that setting was even changed to begin with. O_o

• Started Firefox in troubleshooting mode; still no sound.

• Started Firefox in a different profile; still no sound.

• Started Firefox in private mode; still no sound.

• Tried ending the audiodg.exe process in task manager and restarted; still no sound.

• Double checked media.autoplay.blocking_policy, was set to 0.

• Double checked media.block-autoplay-until-in-foreground -- changed from true to false, restarted Firefox; still no sound.

• Disabled hardware acceleration; still no sound.

• Refreshed Firefox; still no sound.

• Complete uninstall, including the usage of BCUninstaller to uninstall "leftovers". Reinstalled. Still no sound.

I have Apollo installed on my computer and I've reached out to them before for similar issues, but the dev was insistent that Apollo does not cause sound issues. I'm somewhat sceptical, but they're not being helpful at all so I thought I'd ask here, and disclose usage of Apollo so that all bases are covered.

Thank you for your time.

I am using Firefox on gnome desktop on the PureOS variant of Debian. About three days ago, I went to listen to my Spotify playlist on Firefox, not through the Spotify app. I had no sound, checked my system settings and turned the volume for Firefox from zero back up to normal. The rest of the song played, but when the next song came on, again no sound. I watched the sound settings and when the song finishes, Firefox disappears from the sound settings list. When the next song starts, Firefox is back in the list but volume is set back to zero. I suspect this may be something in gnome, but I thought I would check here in case anyone else is seeing this issue. Thanks so much for any help or at least a shoulder to cry on :D

The video from certain sites(not one, but multiple ones) plays as gibberish. Attached a sample from amazon prime. Tried the following

• System restart
• Bios/Firmware update
• Display driver update
• Windows refresh

The issue seems very much localized to Firefox and not seen in any other browsers.

Hi, when I launch a custom video player on a certain site and go into full screen mode, and then want to exit it through ESC, I can’t do it and the picture freezes. I went to the browser console, and it gave me this error: Uncaught (in promise) TypeError: Not in fullscreen mode

   cancelFullScreen https://interneturok.ru/assets/custom-2dc6965f3c367b4e4590249bd2036dfc.js:578
   hotkeys https://interneturok.ru/assets/custom-2dc6965f3c367b4e4590249bd2036dfc.js:675
   dispatcher https://interneturok.ru/assets/custom-2dc6965f3c367b4e4590249bd2036dfc.js:131|

The technical support of that site told me to write to the browser support, I understood the problem is not on their side. I tried everything and went through incognito mode, the problem did not go away. Give me some advice or maybe the problem is with this site and not with the browser, I also tried to launch this video player through Google Chrome and there were no problems there

This is what the GPTchat wrote about the error from the console: Yes, this error is directly related to exiting fullscreen mode. It says that the custom-2dc6965f3c367b4e4590249bd2036dfc.js script on the site is trying to exit fullscreen when the browser thinks it is no longer in it.

That is, Firefox has already exited fullscreen mode, but the player itself "thinks" that it is still there. Therefore, when you press Esc, the script calls cancelFullScreen(), and the browser throws the error "Not in fullscreen mode".

Plus screen Error

!. link to youtube only flashes then plays only audio. Full video requires opening link in a new private browser window

2. Typing into search bar for Duck Duck Go in new tab page types directly into active bar...

3. Active bar is no longer at the top but is in Bookmarks toolbar...

I suspect some update problem.

I have HDR working in Proton games and mpv fine (using Plasma 6.4 / Wayland)

I enabled HDR in Firefox (gfx.wayland.hdr), and HDR content works in YouTube fine ( looks amazing!) however.. I have an issue in that all non HDR content doesn’t show any video (I have sound) just a green sceen (see screen shot) including all ads.

Any idea how to work round this ?

I have AMD 7800 GPU .

Cheers

Since Flathub list the org.mozilla.firefox app as official, i hope this is the correct support channel.

Recently i switched from distro specific package managers to flatpak as my application provider. The firefox flatpak won't play most embedded Video/Media on applications like in-browser fediverse clients, forums, blogs or wikis. Youtube works without any issues, Twitch is fine until there is an adbreak. Then it sometimes stops with the supported format/mime error (screenshot appended), only recoverable by cache-dismissive reload.

I used this Article https://support.mozilla.org/en-US/kb/audio-and-video-firefox and the links it contains to debug without any success. None of these samples play. just shows supported format/mime error https://test-videos.co.uk/bigbuckbunny/mp4-h265 At this test website 1. and 3. example won't play. I provided a screenshot before and after trying to click play on all the examples. https://www.tekeye.uk/html/html5-video-test-page

Contrary to the observed behavior about:support#media claims Software Decoding supported for everything except HEVC.

Chromium Flatpak has no such issues. So i copy the video url and play it with chromium. You can see: dire times.

Videos on Bluesky have never appeared for me, instead they all say "Your browser does not support the video format. Please try a different browser." This seems to happen regardless of the video source.

Reposting until I get help from someone. Windows/desktop. On Google Chrome, any streaming website I used with autoplay enabled would KEEP full screen mode ON after changing episodes. It would automatically go to a new page with the following episode and remain full screen. Why doesn't Firefox have this feature?? I'm seriously considering going back to Google Chrome for this one small feature. Every time I had any streaming service playing with autoplay enabled, I didn't have to manually select the full screen option every time. I am having to stand up and manually click full screen function. Every. Single. Time. Somebody please help me if there's a way to active that function.

I have noticed recently that when i try to play certain videos i am sent that are embedded on webpages the screen just goes black and i cannot see anything but i can still hear the video playing in the background. Why is this happening. I have a new HP envy laptop and am using firefox browser but when i use my work laptop which does not have firefox (IBM Thinkpad) i do not face this issue therefore i assume it is a setting in firefox

Youtube brought up in the broswer works fine with audio/video but on other websites I can view the video and can't hear the audio.

https://www.cnn.com/2024/12/15/us/drone-sightings-east-coast/index.html?iid=cnn_buildContentRecirc_end_recirc