Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

It seems that it was the unusual behaviour of the Flashblock plugin which caused the problem. Thanks a lot.

I don't have the flashblock plugin installed, but I have the same problem. I click "play" on a song or album on myspace, the player window pops up and it gives this message:

Flash is unavailable for playback. Your Flash version is: 11.1.102 To proceed, try the following:

   Refreshing the Page
   Restarting your Browser
   Upgrading your Flash Player

I do the same thing in google chrome and it plays no problem. But this is the only website where I've encountered a problem with flash player on firefox.

Google Chrome comes with its own Flash plugin, so doesn't require and external plugin to be installed like Firefox needs.

Test if you have the Flash player installed and working.

• http://www.adobe.com/software/flash/about/

• https://support.mozilla.org/kb/Managing+the+Flash+plugin
• http://kb.mozillazine.org/Flash

I have the plugin installed, and it works properly on every other website that I have been to. The myspace music player is the only problem I've experienced so far.

I too have the problem, and running in Safe Mode and disabling various things does not make it go away. Internet Explorer and Google Chrome both work OK. My experience otherwise is the same as MisterEwok's.

Same problem with Firefox 6.0 on Solaris and iceweasel/Firefox 8.0 on Debian. Chromium-browser on Debian works OK.

Same problem. I have FF 10 and the newest flash which is working

http://www.adobe.com/software/flash/about/

FF 10 is in safe mode and I still get the same message in MySpace "flash cannot be played". IE works fine!

I'm rephrasing this. It's Myspace that is not working with Firefox. http://www.espace.mu/ (Radio-Canada) exhibits the same behaviour. I just stopped using them.

answer is coming...

I have the solution!

Firefox needs the following certificate to let myspace player work: http://www.globalsign.com/support/intermediate/organizationssl_intermediate.php

http://eigene.dyndns.org/download.php?file=GlobalSignOrganizationValidationCA.crt

I asked the german firefox support chat and they have found it. I don't know why it is so. How to import the certicficate: from my german ff in english:

preferences>Settings>Advanced settings>encoding>'show certificates'>import

Thanks! Solved for Myspace with iceweasel/FF 8.0 + libflashplayer.so 11.1 or 11.2 on Debian PC's.

P.S. Problem with espace.mu was unrelated. Fixed by accepting third-party cookies.

Me too!

Fixed my: "Flash is unavailable for playback. Your Flash version is: 11.1.102 To proceed, try the following:

  Refreshing the Page
  Restarting your Browser
  Upgrading your Flash Player"

Problem by importing the Certificate Tools-> Options-> Advanced -> Encryption -> View Certificates -> Import Select file Checkbox Identify Websites (from memory, so maybe incorrect, it was the 1st check box)

Thanks! vw66bus