Have started to get this error. I'm syncing between calendar on server (one.com) and client Kubuntu 20.04
The problem is always with a public holiday item.
Syncing khal_sync/calendar
error: Unknown error occured for khal_sync/calendar: /calendars/users/bill-
[email protected]/calendar/ca6af7456b0088abad9a69f9f620f5ac-2021-01-01-
[email protected]
Any ideas would be welcome since vdirsyncer has been working flawlessly for a very long time now.
Although there was no item either on the server or on the client, exporting the server calendar enabled me to examine the entire conten of each ics item. A event was found that somehow had the offending reference (ca6...etc) in it's URL field. Removing this item from both server and client results in a clean sync.