Can you post a link to a page that gives you this message?

You may need to install the Gecko Media Player plugin.

• https://support.mozilla.org/kb/Using+the+Windows+Media+Player+plugin+with+Firefox

OK, a page I'm looking at now is http://www.lawyersgunsmoneyblog.com/ You have to scroll down to the section titled: “The Bear and the Maiden Fair”: an LG&M Game of Thrones podcast featuring SEK and Steven Attewell. Immediately below the word "Enjoy!" is a gray area with the broken plug-in icon and "A plug-in is needed to display this content" and a link to plugin finder. A plug-in finder window started up, ran for about fifteen minutes, and just disappeared without any message. Ad-block Plus tells me it's something from YouTube, but I've got other YouTube videos working fine in the pages above this.

Well, this is weird. I clicked on the link, which took me to http://youtu.be/UTS-OTPkxqs . When the page opens I get the same, "you need a plug-in to view this page", but then it goes ahead and plays in the YouTube player. There's no "share" section giving a url for linking, but in the description it says this is "...yet another Lawyers, Guns & Money podcast, all of which can be found here: http://lawyersgunsand money.comic" A podcast packaged as a .comic file? Are you kidding me? This is what I've been wasting my time all day on? And now that I can see a little bit of it I'm not even interested. These guys are deeply, seriously, interested in the mechanics and techniques of movie-making, and I don't car about those things.

Is there a plug-in for *.comic files?

That is a Flash object and a mp3 podcast as you can see if you inspect the page source.
The Flash player should be able to show the first and the MPlayer or Gnome Media player should be able to play the mp3 file.

<object height="533" width="710">
<param name="movie" value="http://www.youtube.com/v/UTS-OTPkxqs?hl=en_US&version=3&rel=0">
<param name="allowFullScreen" value="true">
<param name="allowscriptaccess" value="always">
<embed type="application/x-shockwave-flash" src="http://www.youtube.com/v/UTS-OTPkxqs?hl=en_US&version=3&rel=0" allowscriptaccess="always" allowfullscreen="true" height="533" width="710">
</object>
</p>
<p><a href="http://lawyersgunsmoneyblog.com/podcast/gots03e07.mp3">The audio version for thems that only have ears</a>.</p>

I thought I posted this once. If this is a duplicate posting, sorry about that.

This is embarrassing. I thought I had Flash installed. I've been watching YouTube videos and videos on other sites, so I didn't really pay attention to my list of plug-ins. Last month I re-installed Ubuntu 12.04, which created a new installation of Firefox. Firefox is the default browser for Ubuntu, but Flash must be installed separately.

In Ubuntu the only way to install Flash is to install the package "flash-plugin-installer" There may be ways to manually install he Flash Linux package from Adobe, but I haven't gone there. Just install "flash-plugine-installer" either through the Ubuntu Software Center, the Synaptic Package Manager, or command-line, "sudo apt-get install flash-plugin-manager".

Thanks so much for the time you took to help me.