First reset your Firefox preferences and check the update. If you can't able to update via firefox. Go with clean install.

Reset : https://support.mozilla.org/en-US/kb/reset-preferences-fix-problems

If there are problems with updating or with the permissions then easiest is to download the full version and trash the currently installed version to do a clean install of the new version.

Download a new copy of the Firefox program and save the disk image (dmg) file to the desktop

• Firefox 16.0.2: http://www.mozilla.org/en-US/firefox/all.html

• Trash the current Firefox application (e.g. open the Applications folder in the Finder and drag the Firefox application to the Trash) to do a clean (re-)install
• Install the new version that you have downloaded
• https://support.mozilla.org/kb/Installing+Firefox+on+Mac

Your profile data is stored elsewhere in the Firefox Profile Folder, so you won't lose your bookmarks and other personal data if you uninstall and (re)install Firefox.

• http://kb.mozillazine.org/Profile_folder_-_Firefox

Cor-el, I can't trash my current version of FF. When I try I get a message that FF is locked and can't be trashed. Do you know how I can unlock FF in order to try your solution? Thanks.

Did you check the settings in the Finder for the Firefox application folder?

You can also try to repair the disk permissions:

• http://thexlab.com/faqs/repairprocess.html

I don't know what you mean by the settings in the Finder for the FF application folder. There's nothing about FireFox in my system preferences, so I guess you're talking about something else, but if you could be more specific it would help. Thanks.

See http://en.wikipedia.org/wiki/Macintosh_Finder

Well, I've learned a bunch, but my actual solution path may be of interest to some. After finding online the key I needed to enter in Utilities:terminal, I reset FF, but still couldn't get updates. After repeated attempts to trash FF and getting messages that I couldn't trash it because it was locked, I did a 'secure empty trash' and when I got a message about locked files I selected delete all files. I then downloaded FF 16.0.2 and realized that I hadn't done anything to save my bookmarks, painstakingly assembled over several years. But when 16.0.2 opened up, there were all my bookmarks. Oh yay! Uh, except, where did FF get my old bookmarks? Do they keep all my private stuff in their files too? If anybody has an answer for this I'd sure like to hear it. I'm glad I have 16.0.2 (assuming it will do automatic updates) but I'm leery of a corporation keeping my personal info without my knowledge.

Your personal data is stored in a different location in the Firefox Profile Folder and not in the Firefox application folder, so removing the latter doesn't affect bookmarks and other data.

You can use this button to go to the Firefox profile folder:

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

• https://support.mozilla.org/kb/Backing+up+your+information

Cor-el, I really appreciate your help at every turn. Thanks a ton. Hope you have a Happy Thanksgiving.