I-Firefox Community Forum

I just upgraded Firefox to version 156.0.2.

It no longer plays mp4 content from a website. It says "No video with supported format and mime type found".

This used to be OK.

Media resource could not be decoded, error: Error Code: NS_ERROR_DOM_MEDIA_DECODE_ERR (0x806e0004) Details: virtual mozilla::MediaResult mozilla::FFmpegVideoDecoder<62>::DoDecode(mozilla::MediaRawData*, uint8_t*, int, bool*, mozilla::MediaDataDecoder::DecodedData&): avcodec_send_packet error: Unknown error occurred

When I full screen in YouTube, Firefox makes a Fade in animation. Can I disable it and make the default animation works?

Note: I notice that Firefox on Linux doesn't have this feature, I don't know why this feature is only for Windows.

System Information: Surface laptop has Windows 11.

Quality switches to 360 when tab inactive firefox. I watch Twitch in 1080p. When I switch to another tab and then return, the quality drops to 360p and then automatically goes back to 1080p.

Good evening Mozilla,

Well I am facing an issue, no sound coming from any website like netflix or youtube or prime from mozilla browser.

Could you please fix it for me.

Regards

Browsing this website article I can see that there are embedded Youtube videos in the article but they are not loading, instead I only see blank spaces. I've turned off all extensions, turned off tracking protection, cleared cache and cookies for both the website and Youtube.com, and tried viewing the website in troubleshoot mode.

There is an issue with MKV video playback with MP3 audio track in FireFox. The problem is that MKV video plays MP3 audio track without any sound. With AAC audio track the problem is that MKV video initially downloads whole video and only then plays it. In comparison with MP3 and AAC the benefit of MP3 is much better quality and it starts playing without downloading whole video like MP4.

It would be nice if you add support MKV video with MP3 audio playback.

Video file link: https://v01d.have.lv/vp/movies/test/fm/al.mkv

Hello, I did a lot of search and followed all these advises: https://support.mozilla.org/en-US/questions/1229615 https://winaero.com/remove-your-browser-is-being-managed-by-your-organization-from-firefox/

1. I have not entry "DisableFirefoxAccounts" in "HKEY_CURRENT_USER\Software\Policies\Mozilla\Firefox". 2. I have no policies.json file in firefox directory. 3. I have a message "Your browser is being managed by your organization." in "Settings" (about:preferences). 4. In "about:policies" I have DisableFirefoxAccounts=TRUE. 5. in "about:config" identity.fxaccounts.enabled=false and grayed out.

Please help me to turn on the sync of bookmarks. All these listed issues obviously have something to do with it.

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.

!. 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.

Facebook videos in Firefox stop playing when clicking the Windows 11 Start button or opening Solitaire (after recent update)

This issue has just started after a Windows 11 update and restart. It has never happened before. I usually watch Facebook Reels while playing Solitaire at the same time — yes, I know, I don’t have a life.

This morning, after the update and restart, I opened Facebook and started watching a Reel as normal. As soon as I clicked the Windows Start button to open the list of programs, the video stopped. I then selected Solitaire, which opened to the taskbar. I restarted the video, clicked Solitaire to open the game fully, and the video stopped again. As soon as I minimize Solitaire, the video resumes playing.

I’ve tried all the suggestions I could find via Google, but nothing has worked so far. Note that this only affects videos playing directly on Facebook — videos playing in the Windows Media Player Legacy video player itself are not affected.

Any help would be greatly appreciated… and yes, as mentioned, I clearly don’t have a life 😅 Link to video showing what happens when I select Solitaire in the Taskbar. https://drive.google.com/file/d/1oKLIl3I4f9lfTZvbU-9pJ1gMbOU7h0zm/view?usp=sharing

Regards everyone.

More info... I run two monitors and it seem if I click on whatever I have open in the second monitor the FB video stops. So something has changed after I turned my computer on this morning and updated Windows. I even did a System Restore to a setting two days before this new update and nothing changed still have the problem.

Trouble with streaming services(like youtube(only streams ), twitch, music streaming) on nightly Firefox Nightly 145.0a1 (2025-10-11) (x64) Cachy OS Binary from firefox.com