Ok, this one is a carry over from LiveChat. We had to end early (it was 2 AM!) and so I'm posting what I've found out here and invite further suggestions.

Here's the issue:

Firefox works fine, until after the 2.0.0.12 update. Now, when he goes to Tools>Addons and tries to click on an Options button for any add-on, the window freezes. Furthermore, the entries in the Tools menu to directly change the extension settings are gone. This is for all the extensions. Dialog boxes in general (Tools>Options, and subdialogs from there) still work, so it's not that.

What we've tried: well safe mode works and disabling Tab Mix plus didn't fix it (since that was the extension he wanted to edit in the first place). Default theme doesn't work. Deleting extensions.* in the profile folder doesn't work. (Yes we closed Firefox first). Restarting doesn't work.

What we're saving 'til the very end: New profile. If you have any suggestions that don't involve a new profile, post them here.

Greg: If there are no further suggestions here, Profiles and Managing profiles discuss how to make a new profile. Try in a new profile and if that works, this link tells you what files to move to the new profile, or come find someone on LiveChat to help walk you through it.

Do the popular themes have spyware attached to them? Can I load a theme without loading some sort of virus?

To Bo and Cww
Thanks for all of the help. FF now seems to be working fine. I ended up creating a new default profile. I first backed up my old default profile on a flash drive. Then I tried creating a new profile named Gregb. I saw it show up on Windows Explorer but when I went back to FF Profile Manager, it would not appear - ????? Anyway, I ended up deleting the default profile and also the profile.ini file. FF then created a new default profile and I copied bookmarks, cookies, etc. as detailed in "this link" Cww noted above. FF now seems to working fine with tab mix plus(TMP). When I go to the tools menu, TMP Options shows up under Tools. Also, when I go to the Add-ons under Tools, the Options button works just fine.

Not sure why I could not see the other profile I created when I went back into the Profile Manager. It was located in the same directory location as the default Profile.

Anyway, Thanks again for all of your help

I just wanted to report that Greg's solution to create a new default profile by manually deleting the existing default profile folder and profiles.ini file also worked for someone else:

http://forums.mozillazine.org/viewtopic.php?t=627499
addons not working after upgrade

Bleddyn:

Please start a new thread for your problem.
Then you also can provide information about your plugins and extensions (Tools > Add-ons) and we will be better able to help you.
Thanks!