Alright, I had to delete FireFox on my Mac because a lot of things stopped working after I installed FireFox.
I couldn't even download pics from my camera and I couldn't go to some of my websites.
Now the issue is resolved.
The only issue I seem to have at this point is I couldn't change display picture (Avater) in Microsoft Messenger.
I go into Personal Setting < Change Display Picture and I selected the Avater I wanted to use, but nothing happened after I clicked on "OK" button. The "OK" button is disabled, I had to click on "Cancel" in order to close the window.
Is there a way to fix this? Thanks