-> click Firefox button and click Exit

-> Start Firefox in Safe Mode (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

https://support.mozilla.com/kb/Safe+Mode

Firefox Safe Mode window will open. DON'T SELECT ANY OPTIONS, just click Continue in Safe Mode

Check and tell if its working while you are in Safe Mode.

It seems to work properly in the safe mode.........I noticed a typo in my original post. I've got the latest version of Firefox installed, not 4....

So did the error showed again when you exit the Safe Mode, Restarted Firefox and ran it like you Normally do ??

yes, when I restarted still got the error box message....

Troubleshooting extensions and themes

https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes#w_the-problem-does-not-occur-in-safe-mode

Check and tell if its working.

When I went to the add ons manager and clicked on appearance and extensions, it said I didn't have any add ons of that type installed.........The things with hardware acceleration made no difference....

This type of error is usually caused by an add-on you are using that is not compatible. It could be anything from an antivirus link scanner like AVG Safe Search add-on, or McAfee Site Advisor add-on, or something similar. To confirm what add-on is causing this use the procedure in this link:

https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

Try Disabling the last add-on that was installed prior to upgrading to version 5.0

Check and tell if its working.

I disabled each add on, one at a time, restarting firefox after each one. Didn't make any difference. I'm thinking maybe to uninstall firefox and reload. Hate to go through the drill of saving bookmarks, etc to get that done.........

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.com/en-US/kb/Basic%20Troubleshooting#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"

Check and tell if its working.

OK.......the fault is in the profile, the new one worked fine. Is there an easy way to copy over my bookmarks and passwords?

Recovering important data from an old profile

https://support.mozilla.com/en-US/kb/Recovering%20important%20data%20from%20an%20old%20profile

Check and tell if its working.

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