Hello,

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Thank you.

Thanks for the reply, but, I've already done the reset function-twice, with no effect. I keep the cache clean, but, that only intermittenly has worked. I'm replying from my IE9 browser. I had it for today, I've already spent, at least, 4 hours trying to figure this out. I even installed FF 19 and I'm still having the same problem. I did a system point restore before this problem happened and everything was working well until FF deactivated FP 11.3 again.

Ok, well let's try a shotgun approach here:

Upgrade your graphics drivers to use hardware acceleration and WebGL

Troubleshoot Firefox issues caused by malware

And then disable protected mode in Flash Player. http://forums.adobe.com/message/4468493

Thanks again for your prompt reply. I ran AVG, SAS, MAMB, and none of them found any bugs. I also checked the graphics driver and they are current and the folks at Dell support confirmed that. The only thing left to do is to disable protected mode which I'll try when I'm in a better frame of mind. By-the-way, as I mentioned I uninstalled FF20 and went back to FF19 and so far I'm not seeing any problems yet. Perhaps there's a problem with FF20 and FP??

Just was looking at the protected mode function. I found the mms.cfg file but when I tried to open it to edit I got a pop up message saying it didn't know what program to use to open the file. Now what? By-the-way, so far I've had no problems with FF19 and FP11.7, as of yet. I'm now beginning to wonder if there's a bug in FF20.0.1 causing all this problem. I'll keep you posted.

Use notepad or some other plain text editor to open the File.

You should be using Firefox 20 as it is more secure and more stable than 19, so we need to get you updated and working with 20 :)

Same problem occurred with FF19, this AM, so I updated to FF20 as you recommended. I was able to open the cfg file and tried to add the line about protected mode, but, when I tried to save the change I got an "access denied" pop up. So, I'm stumped as to how to get access. I'm using Vista. By-the-way, when the screen freezes the only way I can get FF working again is to do a reset.. I look forward to your comments. Thanks

Well I had it. The protect mode thing does not work. I guess I'm going to have to use IE9 until Firefox and/or Flash figure out how to fix this problem.

After spending more than 8+ hrs trying to FF20 and FP to play nice with each other I finally gave up. I've tried everything suggested and then some and FF20 still freezes. The only solutions I have are as follows: run FF with FP disabled, or use IE9 or Chrome, which have no compatibility issues, what-so-ever, with FP. I had a version of FP, 11.3.300.268, which actually worked, but, FF flagged it as unsafe which it probably is, but, it worked. I have to lay the blame for this compatibility issue at FF's feet. It's been going on way too long. I really do like FF, but, I've spent enough time trying to get it too work. Does anybody know when this issue will finally be fixed??

I was having the same problem for third day now, searched everywhere for solution and tried them all, first it was script not reacting, later I decided it must be flash causing freezes, then I suspected graphic drivers so I disabled hardware acceleration, disabled everything what could be disabled, reinstalled GPU drivers, still problem persisted with FF 20.0.1 I got tired finally and switched to IE. Horrible decision, but they are all in horrible times :) but I couldn't get past my start page with FF.

Finally, today I tried last resort, uninstalled flash player, then reinstalled it back, and there it was, the solution was very simple, removing and installing new version of flash player solved the problem. Now, I am angry about this and about bloody flash causing SO MANY TROUBLES!

Maybe the folks at FF will take heed and fix the problem. I use Chrome and IE9 that have no issues to FP. I'll consider coming back to FF once they finally address this problem. Are the folks at Firefox listening??