Have you tried safe mode? Hit and hold option as you launch firefox. If that allows it to open and not freeze, I'd clear the caches, etc after that, and exit/re-launch firefox to see if that cleared it.

If it still freezes up, you might want to disable all your addons (again in safe mode), and exit / relaunch again. If it works now, keep enabling add-ons until the problem occurs. Chances are the issue will be with the extension you just added.

If none of that works, could firefox or the extensions be corrupt? I'd try doing regular disk maintenance/ repair on your computer and re-install firefox and all extensions from a clean copy.

Hi, thanks for trying to help... but I don't know what you mean by hit & hold option... where is that? Or how do I get to safe mode? Also, I don't have a "clean copy" of firefox, because I downloaded it from the internet a long time ago.

It is possible that there is a problem with the files sessionstore.js and sessionstore.bak in the Firefox Profile Folder.

Delete the files sessionstore.js [2] and sessionstore.bak in the Firefox Profile Folder.

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

If you see files sessionstore-##.js with a number in the left part of the name like sessionstore-1.js then delete those as well.
Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost, so you will have to create them again (make a note or bookmark them).

See also:

• [1] http://kb.mozillazine.org/Session_Restore
• [2] http://kb.mozillazine.org/sessionstore.js

Hi again, I figured out how to get to safe mode; trying a couple of things there, will probably just uninstall Firefox and then try to download it back on. Thanks for all your help! :-)

Thanks to you too Cor-el. I'll try your solution if uninstall & re-install doesn't work. Again, thanks!