Thank you for the crash report link. I'm not sure where the problem is, but it could be with the Baseline JavaScript compiler.

Could you try starting up Firefox in its "Safe Mode"? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox, including the JavaScript compilers. More info: Diagnose Firefox issues using Troubleshoot Mode.

You can start Firefox in Safe Mode (assuming Firefox is fully shut down) by holding down the option key while starting Firefox.

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

Any difference?

This could also be a problem with one or more prefs. You can inspect and modify preferences on the about:config page.

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.

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)

See also:

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