Riva displays the following error:
Skipped Appointment in [Exchange, Google, or IBM Notes] - Skipping detected CRM change for a deleted or declined appointment that originated in [Exchange, Google, or IBM Notes]:
This error occurs because although the appointment was deleted, it still exists in the mailbox with the "CRMID" — the unique ID Riva attaches to each message, appointment, contact, etc. The CRMID links back to the corresponding CRM item. Riva adds this ID to each item and syncs to a hidden field in the mailbox. This is true for Exchange, Google, and IBM Notes.
When an appointment is deleted, the items are hidden from the calendar. However, they are often still in the mailbox in some form or other. If you clear your calendar and re-create the sync policy, then when Riva runs the first time sync, it looks for items with a CRMID and encounters this previously deleted item. Riva sees it as a conflict, since the item has a CRMID but was not synced by this new policy. Since not all CRMs support the ability for single users to decline their attendance, Riva skips syncing the item again to prevent it from being re-created and causing potential duplicates that the end user specifically deleted from their calendar.
In a normal situation, this would be the desired outcome, because we do not want items to be re-created after a user has deleted them from one's own calendar.
To allow those previously skipped items to sync: