I have come across this new error after updating itunes. The symptoms are usually music shows that it is synced but will not appear on the phone, the phone will back up but not sync and give you the error 13019
-easiest way i have found to resolve the issue is go into itunes while phone is plugged in. you will have a list of tabs across, summery, info, ringtones, music. select music and where it displays sync music unselect that and hit apply in the bottom right (dont worry your music should be saved on the computer) once the sync is complete re check the music sync option. ive noticed this to work 95% of the time......hope this helps
-easiest way i have found to resolve the issue is go into itunes while phone is plugged in. you will have a list of tabs across, summery, info, ringtones, music. select music and where it displays sync music unselect that and hit apply in the bottom right (dont worry your music should be saved on the computer) once the sync is complete re check the music sync option. ive noticed this to work 95% of the time......hope this helps