On my desktop PC, but not on the laptop, Firefox version 10.0.1 does not play YouTube videos. I get the message "An Error occurred. Please try again later". It may have something do with Java, for which the list of Firefox plugins shows these as enabled and a check tells me that they are up to date:

I'm thinking of uninstalling all three plugins and then install whatever the computer ask me to install when I try to play a video. Would this be the right thing to do? Or should I uninstall and re-install Firefox?

Which Flash version are you using ?

Check here.

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

There are some problems with Flash 11.3 Read here

http://support.mozilla.org/en-US/kb/flash-113-doesnt-load-video-firefox

I have no helpful answer, but I have exactly the same problem.

My solution: using Chrome instead.

Not sure if youtube requires but do you have the current Flash player installed? I use Chrome which installs/updates only for itself and had to download direct from Adobe this week to update for other programs.

ASAIK FF 10 and Flash 11 are incompatible.

Check your flash version. If 11, uninstall and instal 10.

Link for v10: http://get.adobe.com/flashplayer/download/?installer=Flash_Player_10_for_Other_Browsers&os=Windows%207&browser_type=Gecko&browser_dist=Firefox

It could be RealPlayer too, if you have that installed, especially the RealPlayer Browser Record Plugin.

The Flash Player might be the problem. I remember that the computer recently asked me to update it and version 11 got installed:

I shall uninstall it now and then install version 10 and see if it solves my problem.

Adobe Flash Player 10 Plugin installed and YouTube videos now play in Firefox. Problem solved. Thank you all.

I checked what is different on my laptop, which I set up on June 13th, and it has Flash 11 Plugin, but no RealPlayer Download Plugin yet, so there must be some conflict between the two. Or it could be the QuickTime Plugin on my desktop PC, which mozilla.org/en-US/plugincheck/ tells me to update. I thought I'd mention it in case it could help somebody else solve a problem. Perhaps I should have done that update first and am going to do it now, but just the same I'll stick with Flash 10 Plugin for the time being.

Any reason not to upgrade to FF 13.0.1? I'm running it and Realplayer Browser plugin 15.0.5 and Flashplayer 11.1.102 with no problems.

I think flash 11.3 is the problem. I.e the most recent version.

I think flash 11.3 is the problem. I.e the most recent version.

I rarely allow Flash to update until I start having problems with sites due to both stability and security issues that tend to popup with it.

I thought youtube was all html5 players now ?

I thought youtube was all html5 players now ?

Problem is compatibility across all browsers and browser versions. AFAIK, HTML5 is an opt in and the default is still FLASH.

http://www.youtube.com/html5/

On beta channel updates for Firefox. Currently have Firefox 14. No problems. I check for udates to all my programs by using FileHippo update checdker (free program from FileHippo). Try updating first.