For reference and transparency: We have created this report on Apple Bug Reporter on 6 Sep 2016 here: https://bugreport.apple.com/web/?problemID=28172308 Summary: VCard 3 uses folding for long lines. OS X Server Contacts can't parse VCard 3 resources with folded PRODID lines. Steps to Reproduce: Upload a VCard 3 with folded PRODID line, like the following: BEGIN:VCARD VERSION:3.0 PRODID:+//IDN bitfire.at//DAVdroid/1.2.3-gplay vcard4android ez-vcard/0.9.1 0 UID:0ea1c5a9-2c93-443d-8672-0e871710203b@owncloud-service-host FN:John Doe N:Doe;John;;; … Expected Results: The VCard should be parsed correctly. Actual Results: VCard is not parsed. Console error messages: Ignored vCard at /remote.php/carddav/addressbooks/principalname/contacts/0ea1c5a9-2c93-443d-8672-0e871710203b%2540owncloud-service-host.vcf because there is no UID property: "BEGIN:VCARD VERSION:3.0 PRODID:+//IDN bitfire.at//DAVdroid/1.2.3-gplay vcard4android ez-vcard/0.9.1 0 UID:0ea1c5a9-2c93-443d-8672-0e871710203b@owncloud-service-host FN:John Doe N:Doe;John;;; TEL;TYPE=home;TYPE=pref:+1555123456789 EMAIL;TYPE=work;TYPE=pref:john.doe@example.com EMAIL;TYPE=home:from-mac@example.com EMAIL:from-davdroid@example.com REV:2016-08-14T13:18:42+00:00 END:VCARD" Version: OS X Server 5.1.5 Notes: Line folding is defined in RFC 2426 section 2.6, which refers to RFC 2425 section 5.81. Lines longer than 75 characters even SHOULD be folded. Configuration: This report was marked as a duplicate and the problem has apparently been fixed.