Tap here to go to the mobile version of the site.
Your Firefox is out of date and may contain a security risk! Upgrade Firefox

Support Forum

Some HTML5 Videos on youtube won't play


Only recently have i started to get this error message on youtube videos

"Your browser does not currently recognize any of the video formats available."

Its not all of them but most of them give that to me, its quite annoying that i have to load up chrome just to watch a youtube video.

I'm using FF19.0

Additional System Details

Installed Plug-ins

  • Next Generation Java Plug-in 10.15.2 for Mozilla browsers
  • NPRuntime Script Plug-in Library for Java(TM) Deploy
  • Shockwave Flash 11.6 r602
  • Shockwave Flash 11.5 r502
  • Google Update
  • The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
  • Windows Presentation Foundation (WPF) plug-in for Mozilla browsers
  • DRM Netscape Network Object
  • Npdsplay dll
  • DRM Store Netscape Plugin


  • User Agent: Mozilla/5.0 (Windows NT 5.1; rv:19.0) Gecko/20100101 Firefox/19.0

More Information

David Tenser
  • Administrator
  • Moderator
32 solutions 294 answers

Hi there,

Your list of installed plugins reports that you're having two versions of Flash installed at the same time (Flash is the plugin that youtube uses to play videos). One thing you could try is to uninstall both of them and then just install the latest one. This articles walks you through both of those things: Flash Plugin - Keep it up to date and troubleshoot problems

Let us know if this solves your problem!

Cheers, David

Question owner

I disabled the older one (there doesnt seem to be an option to uninstall them in firefox)

And also adobe says i have the latest one 11.6.602.171

Still nothing happened, but isn't this about HTML5? It gives me an error about that not flash.

Modified by shogunreaper

act_deft 0 solutions 1 answers

Helpful Reply

I was having the same problem but I kinda solved it. Go to http://www.youtube.com/html5 and opt out of the HTML5 trial. Now videos should work in YouTube without any problems.

Question owner

yeah that seemed to work thanks

maheshvanol 0 solutions 1 answers

install flash player... Now everything gonna fine...