My iPhone and iPad are failing to sync to the Contacts on my Macbook pro.
iTunes shows a menu to allow syncing, but no information is exchanged.
I'm not using iCloud for my contacts on my iPhone or MacBook Pro but I do want to sync them between both devices. All devices are updated to the latest supported versions of iOS and MacOS as of June 26th, 2018.
This is not my question:
Is there an alternative to using iCloud for managing contacts?
I have been using iTunes without iCloud for years to sync my phone and the contact list on my computer.
I now believe the problem is between iTunes and the Contacts application on the Macbook Pro.
– Changes to groups (add, delete, rename) are not reflected in the iTunes menu for syncing contacts.
– Changes to contacts made on my computer do NOT propagate to either my iPad or iPhone.
– Changes to contacts made on either my iPad or iPhone propagate to the other device when both have been synced.
– Changes to contacts made on either my iPad or iPhone do NOT propagate to the Macbook Pro.
Best Answer
With the help of Apple support I have determined that one of the contact records was responsible. When that contact was removed syncing between the computer and the phone was successful. When that contact was included, syncing failed.
I compared hex dumps of the bad record and good records and I could find no significant differences.