In earlier versions when this used to occur, usually clearing the cache and cooking and restarting firefox used to fix the issue. But this time that doesn't help.

None of the old fixes or workarounds work this time. Firefox support, please fix this. I don't want to move to another browser. But for youtube videos I have to move to Chrome now :(

There are other things that need your attention.

You have a user agent that is corrupted and that identifies you as Firefox/6.0

• Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20100101 Firefox/6.0 BLNGBAR

See:

• https://support.mozilla.org/kb/Finding+your+Firefox+version
• https://support.mozilla.org/kb/websites-incorrectly-report-firefox-outdated-or-in

• http://kb.mozillazine.org/Resetting_your_useragent_string_to_its_compiled-in_default

@cor-el Tried those. Didn't work.

That reply about the user agent is meant for the OP rosti93.

BigMak

Does it help if you (temporarily) switch on Private Browsing mode?

• https://support.mozilla.org/kb/Private+Browsing

Nope it aint it :/

@cor-el, I am facing the exact same problem too. So, chances are that it is happening for the same or very similar reason and if the workaround you suggested works for me, it might work for OP. There you go, rosti93 just confirmed that.

Anyway, I see the same problem in private browsing too.

If it still happens in PB mode then that means that it isn't caused by cookies or the cache.

Create a new profile as a test to check if your current profile is causing the problems.

See "Basic Troubleshooting: Make a new profile":

• https://support.mozilla.org/kb/Basic+Troubleshooting#w_8-make-a-new-profile

There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.

If the new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.

See:

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

If it still happens with a new and unmodified profile then you need to look elsewhere on the computer.

You can try to uninstall and reinstall Flash.

• http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html
• http://www.adobe.com/special/products/flashplayer/fp_distribution3.html

I have found 2 solution...

Go to Firefox -> Add-ons -> Plugins -> Locate Shockwave Flash 11.3.300.257 (not 11.0.1.152) and disable it.

OR

1) Go to Control Panel -> Uninstall a Program -> Uninstall Mozzila Firefox 2) Go to Run (Windows key + R) -> Type appdata - > go to Roaming -> Locate Mozilla Firefox and delete it. 3) Go to C:\Program Files (x86)\Mozilla Firefox (or wherever you have installed it) and delete this folder. 4) download the browser, install 5) Do not update Shockwave 6) ENJOY!!!

cor-el, thanks for your reply but none of those steps helped. Even when I create a default profile, youtube doesn't work.

I uninstalled and installed adobe plugin but it still didn't work. I am yet to try what rosti93did.

rosti93

There is an issue with Shockwave Flash 11.3.300.257 in Vista and later see:

http://forums.adobe.com/thread/1018071?tstart=0

but we did not known you have update the flash to 11.3.300.257 .

thank you

Im using Windows 7 not Vista... apparently there's the same problem....

Yes, i said in vista and later (win 7)

thanks again

@ideato

Thank you so much!! it worked!! yippeeeee

I've tried all of the suggestions here and none work. Does anyone know if this is going to be fixed? Surely version control is sloppy if youtube isn't working.

Ok guys , Since the last update's we got trouble with FF 13 I guess it has an issue with Shockwave Flash 11

Here is what what I did , Go to Adobe flash player page download ( adobe flash uninstaller ) then follow instruction

Once you uninstall your Shockwave Flash 11 Go back to download previous Shockwave Flash version

Then select Shockwave Flash 10 and download

Uninstall Shockwave Macromedia from your Programs and Features If you have it !

After you install a clean fresh Shockwave Flash 10 You no longer will have any problem operating in FF 13 with this previous Flash version

Open FF and go to Add-ons page

only this add Shockwave Flash 10.1.53.64 will be Enabled You may want to Disable any older Shockwave Flash version add

My Flash is 10.1.53.64 Since I am operating in 64 bit

So you have to carefully pick your flash version by your OS requirement

FF will ask you to update your plugins every time you open a website that contains video or flash you'll notice a Yellow bar will appear on the top page

" Some Plugins used by this page are out of date"

DO NOT UPDATE !!

Here is what to do to disable this annoying bar :

Type about:config into the location (address) bar. Scroll down to the entry: plugins.hide_infobar_for_outdated_plugin (or type "plugins" in the filter bar to get there quicker), then double-click the above entry to toggle the boolean value to True.

And no more warnings will appear again unless you may want to to toggle the entry to False now and then, to let Firefox check the out-date of your other plugins, or do it manually via the menus.

So this FIX is simply we just get back to our previous Flash version before updating it to 11 the one with problems until FF checks that issue with Flash 11 , We would be waiting Enjoying out Flash 10 :)

PEACE

Thanks rosti93 your solution works. Well almost.....about 80% of the YouTube videos play, but that is a welcome fix considering I was getting nothing before.

tried all things above but what worked for me was going to adobe site and downloading flash player 11 plugin debug exe.it solved my problems

Thanks q8marronglace

This worked!

Uninstall Flash Player (plugin) 11

Go to http://helpx.adobe.com/flash-player/kb/archived-flash-player-versions.html scroll down and find the first instance of Flash Player 10.x.x.x on the list to download.

I downloaded 10.3.183.20. The zip file has a number of files in it. I chose the Netscape version flashplayer10_3r183_20_win.exe and installed it

Works fine for now..

fpolack, You don't need to get Flash 10.3.183.20 by downloading a huge zip file from Adobe's Flash Player Archive. You can download install_flash_player_10_plugin.exe directly from this link or from the Adobe Flash plugin has crashed - Prevent it from happening again article's "install_flash_player_10_plugin.exe" link. Adobe's How do I revert to a previous version of Flash Player? page also has a 10.3 link which takes to to a direct download page.

Here is the video that shows what needs to be done.

http://youtu.be/oQbu0k0rPwc