Since I've had my late 2013 iMac iTunes crashes fairly often and has to be Force Quit. Also I often get a message saying my iPhone 5s can't be synced. I've updated to the latest iTunes released today with no luck. I did not use the migration tool to import everything from my old iMac to this new one, I dragged my documents and music folders over to try and avoid issues. Anyone have any idea what could be the problem?