Thu, 09 Apr 2026 16:44:58 +0000 https://bugs.horde.org/ticket/14904 read Only Calenders do not work correctly with CALDAV Both Apple ical, as well as thunderbird tbsync did run into trouble with read only calenders. The symptom is the following: The calender will be synced correctly initially on setup of the calender account in the app, but after short time the Application gets an synchronisation error with a 500 Server response to operation CalDAVWriteEntityQueueableOperation The only workaroung I found was to make alle calenders writeable Tue, 05 Mar 2019 15:52:34 +0000 https://bugs.horde.org/ticket/14904#t93291