Separate Security Issue, please update your Flash 29.0 r0 Flash Player Version: 30.0.0.113 Current Version https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, . . . .) Note: Other software is offered in the download. <Windows Only>

Hi, try using a installer from here : https://www.mozilla.org/firefox/all/

What happens when you go to Help --> About  ?

MacOS X 10.9 is definitely supposed to be able to run Firefox 60 according to the system requirements page: https://www.mozilla.org/firefox/60.0/system-requirements/

Maybe it would help to "trash" Firefox 58 first before reinstalling? Please consider making a backup of your settings (profile folder) first "just in case": Back up and restore information in Firefox profiles.

If there is a problem with updating or with the permissions then best is to download the full version and trash the currently installed Firefox application to do a clean reinstall.

Download a new copy of the Firefox application and save the Disk Image file to the desktop Firefox 60.0.2:

• https://www.mozilla.org/en-US/firefox/all/

• trash the currently installed Firefox application (open the Applications folder in the Finder and drag the Firefox application to the Trash) to do a clean reinstall
• install the new version that you have downloaded
• https://support.mozilla.org/en-US/kb/Installing+Firefox+on+Mac

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you reinstall or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

Clean install fixed the problem.

Also updated Flash per PKShadow which might have helped with the fix.

Thanks to all.