I encountered am error when syncing my mobile phone’s address book with ownCloud:
PHP Fatal error: Call to undefined method OCContactsVCard::deleteFromDAVData() in /path_to_owncloud/apps/contacts/lib/connector_sabre.php on line 194″ while reading response header from upstream, client: 0.0.0.0, server: your-server.tld, request: “DELETE /owncloud/apps/contacts/carddav.php/addressbooks/user/default/number.vcf HTTP/1.1”
It turns out there is a slight misnomer in the code. It has been fixed in the development version, but the fix is not yet part of an official release.
I documented my findings on ownCloud’s issue tracker with step by step instructions on how to fix this until there is a fixed release available.