I can't get KOrganizer to sync more than once with Zimbra's CalDAV server. KOrganizer syncs perfectly when I create the calendar (Settings->Configure KOrganizer->Calendars). After that, KOrganizer can't sync again. I see an error message on the KOrganizer Main Configuration dialog: "There was a problem with the request. The item was not modified on the server. The file or folder zm.isi.edu does not exist (0)".

zm.isi.edu is the name of my Zimbra server.

I can add events to my calendar with KOrganizer but they don't appear in the Zimbra web client.
I can add events to my calendar with the Zimbra web client but they don't appear in KOrganizer.

Zimbra's CardDAV server seems to work.

I'm using KOrganizer in Kontact 4.14.1 and Zimbra 6.x.

I'm not sure how to proceed. Please help me.