This recurrence rule does not generate any valid instances

[Michael Krecek]

I have an event created with Apple Calendar on a CalDAV server with this RRULE:
RRULE:FREQ=YEARLY;UNTIL=20230430;BYMONTH=4;BYDAY=SU,SA;BYSETPOS=-1

When syncing this to another CalDAV server, I get this error message:
`<s:message>This recurrence rule does not generate any valid instances</s:message>

[Hugo]

Is the error the same format as #1052 (comment) ?

This is Sabre rejecting your icalendar event. Everything said in that issue applies here.