Can you start Firefox in its Safe Mode?

On Mac, hold down the option key when starting Firefox to start in Safe Mode.

A small dialog should appear. Click "Start in Safe Mode" (not Reset).

Will it start up and run for longer than the 6 seconds in that crash report?

You can check for corrupted and duplicate fonts and other font issues:

• http://www.thexlab.com/faqs/multipleappsquit.html - Font Book 2.0 Help: Checking for damaged fonts
• http://www.creativetechs.com/iq/garbled_fonts_troubleshooting_guide.html

When I hold the option key down it will come up in safe mode for approx 10 seconds then crash again.

Did you check for issues with fonts?

You can try to delete a possible user.js file and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in the current Firefox release.

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

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

Maybe it is best to keep a backup copy of the prefs.js in case this is caused by a problem with one or more preferences.

See also:

• http://kb.mozillazine.org/Resetting_preferences