Macbook with El Capitan 10.11.5 iPhone 5s with IOS 9.3.2 Music is not syncing. I have tried various USB ports, including two different hubs and going direct. (I get continuous error alert bleeps when I try to connect directly, so I usually use a hub.) Sometimes I get an alert on my iPhone saying the USB cable is not certified (although it's the one that came with my phone). Can anyone suggest what's going on, and why my Contacts sync OK but my Music doesn't?