Forgot to post a link to the video:

https://d3v1vvdy1tkss1.cloudfront.net/system/meca/medium/meca_file/50aa3248bda4b56e19000d4b/gdws1_15.mp4

ME too

http://dimafabor.com/faster1M.mp4

No problems here with both those MP4 files in the built-in HTML5 media player.

Make sure that your security software isn't causing this problem. Boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/

I see that sudogo has created a new thread, so lets continue there.

• [/questions/1046908]

I'm able to reproduce the issue with the MP4 gdws1_15.mp4. See bug https://bugzilla.mozilla.org/show_bug.cgi?id=1133504

If you have problems with current Shockwave Flash plugin versions then check this:

• see if there are updates for your graphics drive drivers

https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

• disable protected mode in the Flash plugin (Flash 11.3+ on Windows Vista and later)

https://forums.adobe.com/message/4468493#TemporaryWorkaround

• disable hardware acceleration in the Flash plugin

https://forums.adobe.com/thread/891337 See also:

• http://kb.mozillazine.org/Flash#Troubleshooting

Read the bug report, it's a bug in Firefox and it will be fixed in FF37+.

I'm using Firefox with 4 profiles. One of them had problem to work mp4. 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.".

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.

Good to hear, Well Done.