Exchange appointment items are skipped due to a "Level-2 conflict".
2016-02-11 07:34:39,272 INFO [CTP-kuy #2861] [1PB3YAMHZAGX] [XA] Level-2 conflict detected on CA2608: Exception of type 'Omni.Sync.Level2ConflictException' was thrown..
2016-02-11 07:34:39,272 INFO [CTP-kuy #2861] [1PB3YAMHZAGX] [XA] Skipped item: Appointment Title [CA2608]
This is a normal condition. Riva reports "Level-2 conflicts" when the following conditions are met:
In that situation, Riva determines that the Exchange item is more recent and skips the update from CRM to Exchange. Riva syncs the update from Exchange to the CRM for that item during the next sync poll.