Recent crashes of certain multimedia contents (this includes Youtube videos, certain flash games and other applications) in conjunction with Firefox are most probably caused by a recent Flash 11.3(and possibly 11.4) update and/or a malfunctioning Real Player browser plugin.

In order to remedy the problem, please perform the steps mentioned in these Knowledge Base articles:

Flash Plugin - Keep it up to date and troubleshoot problems

Adobe Flash plugin has crashed - Prevent it from happening again

Flash 11.3 doesn't load video in Firefox

Other, more technical information about these issues can be found under these Links:

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

http://blogs.adobe.com/asset/2012/06/inside-flash-player-protected-mode-for-firefox.html

Please tell us if this helped!

I have the same problem only on my 32 bit Windows Vista but not on my 64 bit Windows 7. It seems Flash will not start and crash on certain sites but once Flash starts it will work on the problem sites. I wonder if some sites conflict with Flash start up and Firefox. When I go to Adobe Flash site first I then have no problems with flash even on the problem sites. Update: It is now working for some unknown reason. Still have no explanation. It has stopped and started in the past so I hope it continues to work. I had tried all the suggestions with no effect that have been give. Suspect it was a piece of script on the web page that Windows Vista was not handling properly.

Hello - I have this same problem but can give some more information that may help the awesome ones to find a solution...

I run Windows 7 64bit and Flash 11.3 worked perfectly until Firefox auto-installed the new version of Firefox (15.0) this morning. As soon as I restarted Firefox I started to get this problem.

I thought that maybe there was a compatability issue and that I needed to update Flash, so updated to Flash 11.4 and the problem continued.

This morning I've followed the advice of Tylerdowner. Unfortunately, because Flash doesn't work, the Adobe test page doesn't work... So I tried a complete uninstall and reinstall of Flash 11.4 and the problem remains - the only way to stop the message showing repeatedly is to disable Flash in the add-ons manager...

I do have another (old) PC - running Windows XP - and that is quite happily running Flash 11.4 on Firefox 15.0.

I hope this this information is helpful in finding a solution.

I have the same problem but am reluctant to revert to an older version of Flash because it is running perfectly with other programmes on my PC. I am aware of others running Firefox 15 on Windows 7 (64bit) machines who are able to use Flash 11.4 without a problem and am at a loss as to why I can't.

Temporary Solution.

Turn off Automatic Updates in Tools>Options>Advanced>Update and Download and install previous version of Firefox (V14.0.1) from here..

http://www.filehippo.com/download_firefox/download/0d1919444a878f7999e7338f7dd36746/
EditYou may wish to use the official Mozilla Firefox link:
https://ftp.mozilla.org/pub/mozilla.org/firefox/releases/14.0.1/

Everything should then work OK until someone comes up with a permanent solution.

If you have Rapport running see the post by lalunga and install the latest version of Rapport. It has resolved the problem on my machine.

Notes from a forum moderator:

Thanks for the solution egratis. I hope you do not mind if I edit it.

• It is best to avoid using outdated versions of Firefox if at all possible, because they will not be secure, and will increase the risks to your Computer and your Personal Data.
  • see I still want to downgrade — where can I get the previous version?
• Note official sites offer downloads of current and previous versions of Firefox, as noted in the above linked article
• I have:
  put a line through the FileHipo link, and added a link to an official ftp download
  converted the mention of lalunga's post to link

My Firefox has been having issues with freezing since June and I'm sick of it I mean on the first of August it froze but then it was fine until my Avast had an update (23rd) that conflicted with my sandbox program (Sandboxie) but that was quickly fixed then on the 28th I updated FF and shortly after it froze up on me when I was viewing a PDF file so I disabled the protection mode in Adobe Flash and installed a fresh copy of FF v 15 so maybe I should downgrade to FF version 14.1 because like I said that's when it started to freeze again.

Did you disable protection mode because that didn't work for me at least with FF v 15. http://www.sandboxie.com/phpbb/viewtopic.php?t=13280

If downgrading to FF v14.1 doesn't help then I'm going to downgrade my flash player that will have to work.

Same problem with FF15 and the recent auto update of Flash Player. Everything worked fine before Flash update to 11.4 Chrome browser and IE is OK, but I'd rather use FF.

Using Windows7 pro 32 bit.

Seeing as FireFox updated first, then flash, I expect its an issue with the Flash Player.

I've been seeing a lot of people having troubles with Flash And Firefox although the solution is pretty simple- just go to [http://www.oldapps.com/flash_player.php oldapps http://www.oldapps.com/flash_player.php and get an older version, you can try few versions until you find the one that works the best, then you can wait a while for a new version from Adobe and try to update to latest again

I may have to resort to a retro download which appears sensible but Flash 11.4 is running perfectly on my other prgrammes that require Flash including IE 9. It is also apparent that for some people there is no conflict between FF15 and Flash 11.4, including those running on the same OS Windows 7 64 bit as myself. I will use IE9 for a while in the hope that a solution will be found quickly.

I tried to download an older version of flash through oldapps but I got a message from adobe telling me that this wasn't the latest version and basically they stopped me from downloading it. Firefox is practically unusable like this because every page is constantly firing flash error messages at me.

Have now re-installed an older version of Firefox which seems to have solved the problem temporarily.

thedreadpersephone did you download to Flash Player 10.3.183.23,Flash Player 11.3.300.271 or Flash Player 11.2.202.238 because flash player 10.3.183.23 was recently updated on the 21st of August the same day that Flash Player 11.4.402.265 was released and the other two I mentioned were updated on 14th.

Not sure what you mean Baldape. I'm using the most recent Flash Player, 11.4. I tried to go back to a previous one because of this problem but it wouldn't allow me to download it.

Om my Win Pro x64 machine running Firefox 15 and Flash 11.4.402.265 the problem seems to be associated with Trusteer Rapport. If Rapport is running the Flash problem is present and if Rapport is stopped the problem disappears

Hi thedreadpersephone,

Baldape is right. First Uninstall Flash with the uninstaller provided by Adobe and then download and install 10.3.

It is all in the first Tylerdowner's reply : Flash 11.3 crashes

thank you

Um, no. I obviously uninstalled Flash first but I still got the message saying that I wasn't allowed to install an older version.

Anyway, the most recent Flash seems to work with the older Firefox which I had no problems installing so I think I'll stick with that setup for now. In fact the recent Flash works better than the old one which I was having some problems with, whereas the older Firefox seems perfectly adequate. Frankly I don't understand why every programme has constant updates which don't seem any different from the previous version.

thedreadpersephone did you use the uninstaller tool specially made to remove Adobe Flash https://support.mozilla.org/en-US/kb/flash-113-crashes#w_step-1-uninstall-flash that will remove all data for the flash player if you didn't use this tool to remove flash then that's the reason you are unable to downgrade so reinstall flash 11.4 then download and use the uninstaller tool provided by Adobe and PS: don't try using some other uninstaller tool like iObit or Revo you might totally screw up your PC use the attended tool made by Adobe instead. :)

I just used the uninstall option in the control panel. Isn't that the uninstaller that comes with the programme? It never occurred to me to use anything else.

Tbh I'm quite happy with using the new Flash with the old Firefox for the moment. Why would I go back and install a previous version of Flash which doesn't work very well when I can trundle along with the old version of Firefox which works perfectly happily? I'm assuming they will become compatible again at some point.

No, you need to usethe Flash uninstaller.

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

The latest version of Rapport appears to fix the problem. Downloadable from here https://trusteer.exavault.com/share/view/exo-gvdm939m-6r11kbij|