Hello opi1935

1.Disable graphics hardware acceleration.You might need to restart Firefox in order for this to take effect, so save all work first (e.g., mail you are composing, online documents you're editing, etc.).

Then perform these steps:

• Click the orange Firefox button at the top left, then select the "Options" button, or, if there is no Firefox button at the top, go to Tools > Options.
• In the Firefox options window click the Advanced tab, then select "General".
• In the settings list, you should find the Use hardware acceleration when available checkbox. Uncheck this checkbox.
• Now, restart Firefox and see if the problems persist.

Additionally, please check for updates for your graphics driver by following the steps mentioned in the following Knowledge base articles:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

• Upgrade your graphics drivers to use hardware acceleration and WebGL

2.also, disable hardware acceleration in your Flash Player settings.(See this article for more information on using the Flash plugin in Firefox).

To disable hardware acceleration in Flash Player:

1. Go to this Adobe Flash Player Help page.
2. Right-click on the Flash Player logo on that page.
3. Click on Settings in the context menu. The Adobe Flash Player Settings screen will open.
4. Click on the icon at the bottom-left of the Adobe Flash Player Settings window to open the Display panel.
   
   The image "fpSettings1.PNG" does not exist.
   
5. Remove the check mark from Enable hardware acceleration.
6. Click Close to close the Adobe Flash Player Settings Window.
7. Restart Firefox.

This Flash Player Help - Display Settings page has more information on Flash Player hardware acceleration, if you're interested.

3.finally, disable Flash protected mode by following the instructions on these pages:

• http://forums.adobe.com/thread/1018071#TemporaryWorkaround
• http://kb.mozillazine.org/Flash#Disabling_Protected_Mode_in_Flash_11.3

(See this Adobe blog post for technical details about Flash protected mode.)

Please tell us if this helped!

thank you

Thanks for the in depth reply, "ideato".

I disabled the graphics hardware acceleration, but that had no improvement.

With FireFox in safe mode, and Shockwave Flash active, Youtube would still crash. So per the diagnostic, the problem was not caused by an extension, theme or hardware acceleration. So it had to be a plugin.

I uninstalled the Shockwave Flash, restarted Firefox and then tried Youtube. To my astonishment a 15 minute video played flawlessly. I checked the Firefox plugin page and confirmed there was no Flash plugin, nevertheless the video played. Then I attempted to play another video, but no further videos would play thereafter.

Next I installed the newest version of Shockwave Flash 12.0.0.43. Regrettably the Youtube videos continue to crash as if no Flash plugin were available.

Any ideas about this perplexing scenario?

In order to better assist you, we need some non-personal information from you. Do the following:

• Click the Firefox button at the top left, then click the Help menu and select Troubleshooting Information from the submenu. If you don't have a Firefox button, click the Help menu at the top and select Troubleshooting Information from the menu.

Now, a new tab containing your troubleshooting information should open.

• At the top of the page, you should see a button that says "Copy text to clipboard". Click it.
• Now, go back to your forum post and click inside the reply box. Press Ctrl+V to paste all the information you copied into the forum post.

If you need any more information about the Troubleshooting information page, please read the article Use the Troubleshooting Information page to help fix Firefox issues.

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Name: Firefox
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Thanks!

The thing that is bugging me is the DYMO Label Framework Plugin that you have. Do you've got a clue what that is? It's not related to your extensions at all.

The DYMO plugin is related to the DYMO thermal label printer. I'll deactivate that plugin and give Firefox a another go at running Youtube.

BTW, for what its worth, Youtube works on the native Microsoft Exploader.

Note that some videos can be played with the built-in HTML5 media player and this player is used automatically in some case if the web page detects that there is support in Firefox for using the player for this file.

• https://developer.mozilla.org/en/Media_formats_supported_by_the_audio_and_video_elements

Did you try to disable protected mode in the Flash player as that is not obvious from from replies?

See also:

• http://kb.mozillazine.org/Flash#Troubleshooting

Disabled the Flash protected mode, still no go with the videos.

Disabled the Dymo plugin, no change in disabled video status.

Could there be an issue with Windows7 upgrades, in conjunction with FF and Flash?

I have been having issues with Flash player 12, and had to revert back to 11.9 to correct some issues.

I first went here to get the uninstaller:

http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html

then here to get the old versions: http://helpx.adobe.com/flash-player/kb/archived-flash-player-versions.html

Choose:

(Released 12/10/2013) Flash Player 11.9.900.170 (156.2 MB)

open the zip file and run the following under -> fp_11.9.900.170_archive -> 11_9_r900_170 -> flashplayer11_9r900_170_win.exe

I am also running some specialty fixes ( find under my profile ).

I make no claims that this will resolve your problems

Best Regards

Recently, I randomly tried an older Flash version, such as 10.2, and 11.1 etc. In these instances I had to also use an older version of FF. Result, no correction to the problem. So I went back to FF26 and Flash 12. All the Flash video advertisements on Adobe's website work, but not Youtube. Again, only once, did one youtube video play after the software updates. I'm beginning to think that maybe the problem lurks with Windows7 itself. Perhaps some plugin or application, is running in the background? Could this be possible, or is it just my conspiracy theory?

Make sure that you allow cookies and local DOM storage for the YouTube site.

• Click the "Site Identity Button" (globe/padlock) on the location bar
• Click "More Information" to open "Page Info > Security"

• Go to the Permissions tab (Tools > Page Info > Permissions) to check the permissions for the domain in the currently selected tab

You can try these steps in case of issues with web pages:

Reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

• Hold down the Shift key and left-click the Reload button
• Press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• Press "Command + Shift + R" (Mac)

Clear the cache and cookies only from websites that cause problems.

"Clear the Cache":

• Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox/Tools > Options > Privacy > Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

It appears I have solved the problem to the crashing youtube videos. After uninstalling MS Word youtube videos flow smooth.

Now I have a new issue to deal with, installing MS word.

Thanks for the help everyone.

Hello opi1935, it is great you solve the problem, to be honest... we have seen the solution you gave us one more time, in the next question :

https://support.mozilla.org/en-US/questions/985026

yes it is strange, it is add-on as lovegod said in the above link

please mark YOUR LATEST reply (which explain the solution) as the solution, to help other with same problem.

thanks