This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Wannan tattunawa ta zama daɗaɗɗiya. Yi sabuwar tambaya idan ka na bukatar taimako.

No H.264/mp4 video playback (FF57x64 Win10Home)

  • 4 amsoshi
  • 8 sa na da wannan matsala
  • 2 views
  • Amsa ta ƙarshe daga kkkkzk

more options

I can't play videos on Facebook.

I am using Firefox 57.0.4 x64.

Firefox console says:

No decoders: video/mp4; codecs="avc1.4d401e", video/mp4; codecs="avc1.4d401e", video/mp4; codecs="avc1.4d401e", video/mp4; codecs="avc1.4d401f", video/mp4; codecs="avc1.4d401f", audio/mp4; codecs="mp4a.40.5", video/mp4; codecs="avc1.42E01E mp4a.40.2", video/mp4; codecs="avc1.4D401E mp4a.40.2", video/mp4; codecs="avc1.4D401F mp4a.40.2", video/mp4; codecs="avc1.640032 mp4a.40.2", video/mp4; codecs="avc1.640033 mp4a.40.2"

Youtube html5 test says no H.264 and no MSE & H.264.

I'm on Windows 10 Home WITHOUT any "N"-s, so that Windows Media Feature Pack would be missing.

I have tried all solutions presented to similar problems. None of them worked.

How can I make it work?

I can't play videos on Facebook. I am using Firefox 57.0.4 x64. Firefox console says: No decoders: video/mp4; codecs="avc1.4d401e", video/mp4; codecs="avc1.4d401e", video/mp4; codecs="avc1.4d401e", video/mp4; codecs="avc1.4d401f", video/mp4; codecs="avc1.4d401f", audio/mp4; codecs="mp4a.40.5", video/mp4; codecs="avc1.42E01E mp4a.40.2", video/mp4; codecs="avc1.4D401E mp4a.40.2", video/mp4; codecs="avc1.4D401F mp4a.40.2", video/mp4; codecs="avc1.640032 mp4a.40.2", video/mp4; codecs="avc1.640033 mp4a.40.2" Youtube html5 test says no H.264 and no MSE & H.264. I'm on Windows 10 Home WITHOUT any "N"-s, so that Windows Media Feature Pack would be missing. I have tried all solutions presented to similar problems. None of them worked. How can I make it work?

Mafitar da aka zaɓa

None of these did work either. I have wasted so much time on troubleshooting this it turned out that formatting C: was a faster solution :(.

Anyway, thanks for your help!

Karanta wannan amsa a matsayinta 👍 1

All Replies (4)

more options
more options

Thanks for the answer.

Maybe I've constructed that sentence in a weird way, but what I meant was that it is a regular Windows version, with the Windows Media Features installed, so that solution you suggested won't do anything.

more options

Some people have had issues with HTML5 player on Youtube and other sites due to extensions like Youtube Flash or force HTML5 player or such installed in Firefox.

Type about:config with a : in Location (address) bar and make sure none of the below Preferences are user set, if any are then double-click them to restore the default value of true

  • media.mediasource.enabled
  • media.mediasource.mp4.enabled
  • media.mp4.enabled
  • media.ogg.enabled
  • media.webm.enabled

After this try the https://www.youtube.com/html5 page again.

An gyara daga James

more options

Zaɓi Mafita

None of these did work either. I have wasted so much time on troubleshooting this it turned out that formatting C: was a faster solution :(.

Anyway, thanks for your help!