You can check the Web Console for what formats Firefox tries.

• "3-bar" menu button or Tools -> Web Developer
• https://developer.mozilla.org/en-US/Tools/Web_Console

You should have have support in Windows for content type video/mp4. If that fails then check for video issues:

• https://support.mozilla.org/en-US/kb/fix-video-audio-problems-firefox-windows
• https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues
• https://support.mozilla.org/en-US/kb/html5-audio-and-video-firefox

Thank your for your time. I took a snip of the console lines but, this is above my area of knowledge and i am not sure what to make or do about it.

Also yeah i do run a windows N, and the media pack should be up to date, and just to be sure i updated it again without it making a difference.

I have a copy of Google's old compatibility test page here:

https://www.jeffersonscher.com/sumo/html5-video.html

Do you have any that do not say "supported" or "probably"?

Yes the, MP4/H.264 (avc1.42001E, mp4a.40.2): can't be played MSE & H.264 (video/mp4; codecs="avc1.4d401e"): not supported

That usually is due to a Media Pack issue, but if you have the latest version installed, it would be worth checking some Firefox settings as well:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste wmf and pause while the list is filtered

(3) If the media.wmf.enabled preference is bolded and has a value of false, double-click it to restore the default value of true

Please ignore any row with a "+" button to create a new preference throughout this process.

(4) In the search box above the list, type or paste mp4 and pause while the list is filtered

(5) If the media.mediasource.mp4.enabled preference is bolded and has a value of false, double-click it to restore the default value of true

(6) If the media.mp4.enabled preference is bolded and has a value of false, double-click it to restore the default value of true

(7) In the search box above the list, type or paste mediaso and pause while the list is filtered

(8) If the media.mediasource.enabled preference is bolded and has a value of false, double-click it to restore the default value of true

Sadly the problem is not there as all the ones you listed are set to "true". must say i am really getting tiered of N edition, not the first time it have coursed me problems, but this is the first time it have done that without any pattern (at least i can see).

Thank you cor-el and jscher2000 for your time and effort. I finally solved it with your help, i had yet to realize that to correctly update "The Media Feature Pack for N versions of Windows 10", you now have to navigate to Settings > Apps > Apps and Features > Optional Features > Add a Feature and find the Media Feature Pack in the list, i still assumed you had to download it from Microsoft.com and install that file....

Hope this might help another poor soul who happens to own an N edition.

Migomsl, thanks for reporting that the solution was to navigate to Settings > Apps > Apps and Features > Optional Features > Add a Feature and find the Media Feature Pack in the list.

(For the record) One of the Mozilla Suppport articles linked by cor-el (Fix video and audio problems on Firefox for Windows N editions) says that The latest Media Feature Pack for N versions of Windows 10 can be added as an Optional Feature from Windows Settings and links to a November 2019 Microsoft article for instructions.