I keep getting the update message, but have not been able to update.
Download from Mozilla official website.
Hello jwmoss, If there is an issue with update or permissions the better and easiest way is to download and install firefox:
1. Download a copy of the latest firefox from http://www.mozilla.org/en-US/firefox/all.html
2. Trash the current Firefox application to do a clean install.
3. Install the version that you have downloaded.
Do not select to remove your personal data, your profile data is stored elsewhere in the Firefox Profile Folder, so you won't lose your bookmarks or other personal data.
see also: Installing Firefox on Mac
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