Firefox crashes between 5 and 30 seconds after startup, and seems to be more frequent when I quickly go from page to page or go to a new website. It doesn't seem to crash if I stay on one simple page. I have a hunch it is related to Adobe Flash Player, because I've tried to update it several times but it still says it's out of date. (When I try to update, it has me install 10.3, although I think now it is up to 11.3). I cannot run Firefox in Safe Mode either.