I think Flash 14 is still in beta testing. Why was that recommended for you? I'm a day late hearing the news of this release.

Could you check the current status of the plugin? Open the Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins.

Look for "Shockwave Flash" and if it is set to "Never Activate", change it to "Always Activate" to "Ask to Activate".

Apparently I'm behind the times and Flash 14 is now the current version!

In case one of your extensions is interfering, could you test videos in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Diagnose Firefox issues using Troubleshoot Mode.

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

Not all add-ons are disabled: Flash and other plugins still run

After Firefox shuts down, a small dialog should appear. Click "Start in Safe Mode" (not Reset).

Any difference?

I did a 'system restore' and went back to Shockwave flash 13.0.0.214 and Shockwave flash 12.0.0.44 and can see videos now. Something must be wrong with Shockwave flash 14. Can you find out what might cause it not to work???

I installed Flash 14 and YouTube won't play videos on an HTTP URL but it will play on an HTTPS URL.

A YouTube video embedded in an HTTP site won't load, either. In order to get it to play, I need to change the embedding to secure by hacking the iframe tag (or the embed tag inside the iframe).

Regarding Facebook, can you make sure you are using Facebook on an HTTPS connection? Usually you will see the padlock on the address bar.

This is weird. I'm not sure what is causing it. Hopefully someone will discovery that and provide a good solution.

Meanwhile, for videos hosted by YouTube, whether on YouTube itself or embedded in another site, a workaround is to install the Greasemonkey extension and run a user script to switch the URLs from HTTP to HTTPS. I posted an example of such a script here: https://greasyfork.org/scripts/2388-switch-flash-embed-to-secure.

Other sites could be added after a little testing with specific examples.

It seems the extended support release, which is kept up to date with security fixes, is 13.0.0.223:

http://www.adobe.com/support/flashplayer/downloads.html#fp13

For Mac, I think you want the one that says plugin. For Windows, I think it's the second one (when you mouse over the description, the filename contains plugin).

I haven't tried it myself.