Your server sends an invalid redirect:
Considering that my setup was normally working, upgrading to 9.0.2 resolved the issue which was due to upgrade to PHP-7.0.6 - see this link.
Thank you for your response.
everytime I change the notes field of a contact, sync fails (just when I edit the note field on the phone, when editing on the web client everything works).
You can find the debug output in the attachments.
Another info: this contact is synced as Gmail contact and via KolabNow.
This is a KolabNow problem. Can you please report it to them, along with the debug info? CardDAV file names do not have to match the
UID. If the server wants to enforce this, it should use redirects.
@rfc2822 ok thanks for the information I will open a topic in the Kolab forums.