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Firefox 4 won 't play embedded .wmv, have newest plugin


URL: http://www.richardleighton.biz/demo_reel--comedic.html The embedded .wmv file won't play on Firefox 4, even with the latest plugin for Windows Media files...mostly designed for WinXP and not Win 7. Page plays just fine on Internet Explorer and even Netscape, but not on Firefox 4. Played ok on previous Firefox versions.

Additional System Details

Installed Plug-ins

  • np-mswmp
  • Adobe PDF Plug-In For Firefox and Netscape 10.0.1
  • RealPlayer(tm) LiveConnect-Enabled Plug-In
  • RealJukebox Netscape Plugin
  • The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
  • Shockwave Flash 10.2 r153
  • 4.0.60129.0
  • RealPlayer(tm) HTML5VideoShim Plug-In


  • User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0

More Information


MSHogan 0 solutions 1 answers

Helpful Reply

I had this problem too. I eventually traced it to an incompatibility with the Realplayer 14.0.2 extension. When I disabled the Realplayer extnsion WMV files played normally.

I upgraded Realplayer to the latest version, which updated my Realplayer extension to 14.0.3 which resolved the problem and I can now play WMV files normally with Realplayer enabled too.

Best wishes

Mike H

Question owner

Thanks. I've already downgraded back to Firefox 3.6.17 and everything works fine, but I'll try your solution if I decide to go back to version 4. I wish Mozilla had taken the time to work this out prior to releasing version 4 and leaving us to solve these problems for ourselves.

All the best, RL

jamadophoto 0 solutions 2 answers

I converted the files to .mov extensions and now it works fine. I have not tested this on a pc but will have the results by the end of the week. Will let you know.

AltS7 0 solutions 1 answers

For me official wmv plugin works properly on that page. Check in your installation folder subfolder 'plugins' and there NPMSWMP.dll.

I'm using Firefox 4.0.1 on XPSP3\Server 2003 SP2 with WMP11.

Modified by AltS7