Same problem here. My Outlook is running and not closed. 2021-10-05 13:50:17 | Warning | Outlook exception, please assure that Outlook is running and not closed when syncing: 您變更這個項目的某一個發生點而且該發生點已經不存在。請先關閉再重試。 at Microsoft.Office.Interop.Outlook.RecurrencePattern.GetOccurrence(DateTime StartDate) at GoContactSyncMod.AppointmentPropertiesUtils.GetGoogleLastUpdated(AppointmentMatch match, Synchronizer sync) in .\AppointmentPropertiesUtils.cs:line 349 at GoContactSyncMod.AppointmentsMatcher.SyncAppointmentBothExists(AppointmentMatch...