When clicking on a Publication that includes Calendar, the Status displays "Catastrophic Failure". In the CalendarSender.log you see a line with "Catastrophic Failure 0x8000FFFF"
Possible object corruption within the Synchronization.
1. Create a new Publication including Calendar information with a different name than the original Publication.
2. Depending on where you see the error (Branch or HQ), have the Branch or HQ Subscribe to the new Publication.
3. Confirm the Status is now OK and the Calendar Synchronization.
4. Delete the old publication that had the Catastrophic Failure.