Firefox Will Not Start

[TakRail]

Earlier this afternoon I updated Ubuntu and now Firefox will not start. It will show in the task bar that it is "Starting" then that disappears and nothing happens.

Any ideas what I can do?

[TakRail]

Nevermind, I used the command 'firefox -profilemanager' and created a not profile. It's works fine now.

Although I would be interested in learning why it stopped working in the first place.