I cannot watch content, e.g. YouTube, because a banner is across the screen stating "unauthorized content." I've tried everything I know. Also, when I enter my pin, I get a message that it is incorrect. I know it is correct.
That may be coming from your TV. Try a different HDMI cable and/or HDMI input on your TV. Also, try unplugging your TV's power for a minute or two and plug it back in.