No, you're not the only one.
It's been a while that I've been trying to fix this error:

I thought it was just a Youtube error, so I went to the Org and there still was that error, this time with the name (2032):

I did some Internet researches and I tried everything possible: empty the cache, uninstall flash player and mozilla, update java etc..
The problem wasn't solved yet, but the day after I noticed on the Youtube homepage this message:
(You must upgrade your Adobe Flash Player for watching this video. Download it from the Adobe site)And so I did, I downloaded the update, rebooted Mozilla, but the message was still there. Then I disabled the "Schockwave flash" plugin, and several videos have begun to be visible.. but not all of them. Some of them remain with the black screen, others give the same message of the previous image, and then this:
(At the moment, your browser doesn't recognize any video format available.Click here to read the FAQ about the HTML5 video format.)And by clicking that message I get this page:
http://www.youtube.com/html5That thing was active, and I've tried to switch it off, but nothing happened.
I don't wont to switch to chrome!!