My FireFox media player was working fine this morning. Now it will not play the mp3 files I need to play for my work. Also, there's no sound on YouTube when I use FireFox. I have system sounds on my computer, and I have sounds on Google Chrome, but there are no sounds on FireFox. The media player will open with the mp3 files, but it does not move or play at all. I disabled my antivirus and it still won't work. So that is now fully back on. I uninstalled and reinstalled, restarted my computer, I have done so many things over the last 4 hours and nothing is working. There was a Windows update today that happened shortly before this problem occurred.