Re: 2012 730N RHR Issue
Haven't played with the usb or hard drive for music yet, but overall unhappy with that head unit. It just seems outdated and clunky. If I had an ounce of patience in my body I would have searched around for one with something basic and upgraded to aftermarket.
AAC, MP3, WMA from USB, CD, DVD are the formats you can use. Maybe try to convert and see if that works?