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

mp4 problem in Firefox v37.0.2 Windows 8.1

  • 1 reply
  • 1 has this problem
  • 9 views
  • Last reply by Boray Eris

more options

I'm using Firefox with 4 profiles. One of them doesn't work mp4. What could be the problem? When I open mp4 http://www.quirksmode.org/html5/videos/big_buck_bunny.mp4 it says "Video can't be played because the file is corrupted.".

I'm using Firefox with 4 profiles. One of them doesn't work mp4. What could be the problem? When I open mp4 http://www.quirksmode.org/html5/videos/big_buck_bunny.mp4 it says "Video can't be played because the file is corrupted.".

Chosen solution

After I compare prefs.js files of both profiles I saw that "media.windows-media-foundation.enabled" was false. I opened about:config and reset "media.windows-media-foundation.enabled". After restarting Firefox http://www.quirksmode.org/html5/videos/big_buck_bunny.mp4 has been working perfectly.

Read this answer in context 👍 0

All Replies (1)

more options

Chosen Solution

After I compare prefs.js files of both profiles I saw that "media.windows-media-foundation.enabled" was false. I opened about:config and reset "media.windows-media-foundation.enabled". After restarting Firefox http://www.quirksmode.org/html5/videos/big_buck_bunny.mp4 has been working perfectly.