When I try to delete a duplicate calendar from iCloud (I have two named "Home"), Calendar.app throws a fit and gives this error: I tried signing in and out of iCloud, both on my iPhone and Mac, deleting the calendar elsewhere, and disabling Calendars. None of this worked. I am using the same email address between accounts. This is an issue that has been asked about through the Apple Discussion site but no consensus was ever formed. I don't want to ask them for help because I feel I'll get the run-around. How do I fix this?