I am a freelancer and often receive meeting invites from my clients who are typically larger organizations and run exchange or some other enterprise system. The meetings go into iCal fine, but often updates to the event (time change, adding a location) fail and I get the following message: The server responded with an error Access to <event Name> in <calendar name> in account iCloud is not permitted. The server responded: 403 to operation CalDAVWriteEntityQueueableOperation. This is a bit random, some events from within the same organization update fine, others give this error. Any tips would be greatly appreciated!