Hmm, could you check the address bar for the plugin notification icon? This should appear to the left of the page address and typically looks like a small, dark gray Lego block. When the plugin is subject to a security block, the icon turns red to alert you to the concern. Assuming you see that icon, if you click it, does it show that Flash is allowed on the current site? If Flash is allowed but the player does not play, a common reason is a content filtering add-on blocking a pre-roll advertisement. Do you use Adblock Plus or similar extension and, if so, could you try creating an exception? Alternately, you could test in Firefox's Safe Mode. That's a standard diagnostic tool to completely deactivate extensions and some advanced features of Firefox. More info: [[Troubleshoot Firefox issues using Safe Mode]]. ''If Firefox is not running:'' Hold down the Shift key when starting Firefox. ''If Firefox is running:'' You can restart Firefox in Safe Mode using either: * "3-bar" menu button > "?" button > Restart with Add-ons Disabled * Help menu > Restart with Add-ons Disabled and OK the restart. ''Both scenarios:'' A small dialog should appear. Click "Start in Safe Mode" (''not'' Refresh). Any difference?