Are you using Flash 11.8?

You can check for problems with current Flash plugin versions and try these:

• disable a possible RealPlayer Browser Record Plugin extension for Firefox and update the RealPlayer if installed
• disable protected mode in the Flash plugin (Flash 11.3+ on Windows Vista and later)
• disable hardware acceleration in the Flash plugin

• http://kb.mozillazine.org/Flash#Troubleshooting
• http://helpx.adobe.com/flash-player/kb/flash-player-113-crash-mozilla.html

I had a problem with youtube videos crashing and finally sorted it out by disabling the plugin container. Type about:config in the address bar and search for dom.ipc Set dom.ipc.plugins.enabled to 'false' I did not need to disable protected mode or hardware acceleration

Note that Firefox will crash if a plugin that doesn't run as a plugin-container process crashes.

You may need to check your security software to make sure that the plugin-container process is allowed and has full permissions.

Boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

I'm sorry, but what you say is typical of the replies one gets on this forum from people who think they know better.I have already stated that this fix works. I had tried absolutely everything to stop youtube crashing including what you have said. Youtube was crashing despite the latest flash being installed properly and I have full administrative permissions . Since I have disabled the plugin container I can actually watch youtube videos again and have not had any crashes. As they say the proof of the pudding ..........

To reiterate. I had tried everything suggested on these forums for about a week and nothing worked. After disabling the plugin container my system is now running perfectly and I don't have to switch to Google Chrome to watch youtube videos ( which works perfectly without having to make any changes). There is obviously nothing wrong with the youtube videos and flash but it must be something to do with the plugin container

I started getting this when I upgraded to Firefox 24.0. This web page triggers the problem: http://helpx.adobe.com/flash-player/kb/installation-problems-flash-player-mac.html

You may have to click on the flash box below this text:

"Flash Player information

If Flash Player is installed on your computer, the following box displays the version of Flash Player and your operating system. If Flash Player is not installed, a blank box appears."

in order to see the problem. The flash it is trying to display is: http://helpx.adobe.com/content/help/en/flash-player/kb/installation-problems-flash-player-mac/_jcr_content/main-pars/flash_generic/file.res/widget.swf

I've gone back to Firefox 23.0.1 as it doesn't have the problem. I plan to stay on 23.0.1 until a fix (not a workaround) is available or until someone has a test version for me to try.

I've also attached a screenshot of the Problem Report MacOs produces when plugin-container crashes (or at least the top of it). Let me know if you need more information to debug this. I'm on MacOS 10.8.5.

I forgot to mention I'm on Flash 11.8.800.168. I tried to upgrade to Flash Flash 11.9.900.117 but the upgrade installer has a bug that I've reported to Adobe (the upgrade doesn't work from a standard account, even after you've provided an admin login and password.)

I have since done a reinstall of windows from scratch and now no longer have this problem. Not quite sure what was causing it.

!!! Thanks a million johnboy63 !!!

This stupid youtube video locking up thing has been driving me nuts for far too long, can't even remember how far back it started. I tried all the solutions I could find through hours of searching and nothing worked until your suggestion.