I kept restarting the firefox browser or restarting my computer, trying to make it my default browser. I have lost on how many times I kept trying. But no matter what I do, it still continued to have Safari as default browser. Even when I did the system preferences of having Firefox being its default browser, it still didn't work. Either there's a bug or something else. I need to know how to fix this or I will lose my mind..how can I make it default if it won't let me.