If you have problem to update firefox the best solution 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 [http://kb.mozillazine.org/Profile_folder_-_Firefox Profile Folder], so you won't lose your bookmarks or other personal data. see also: [https://support.mozilla.org/en-US/kb/install-firefox-mac?redirectlocale=en-US&redirectslug=Installing+Firefox+on+Mac Installing Firefox on Mac] thank you