Problem Syncro with icloud Calendar und Calddav

id: Central European Standard Time
08:12:31    bei MailClient.Schedule.TimeZone.TimeZoneConvert.TryGetOlsonTimeZone(String olsonName, TimeZoneInfo& timeZone)
08:12:31    bei MailClient.Schedule.ScheduleConvert.GetTimeZone(TimeZone timeZone, Property dtProperty)
08:12:31    bei MailClient.Schedule.ScheduleConvert.GetTimeZone(DateTimeProperty dtProperty)
08:12:31    bei MailClient.Schedule.ScheduleConvert.UpdateScheduleObjectFromComponent(IScheduleObject scheduleObject, Calendar calendar, ScheduleComponent updatingComponent, ScheduleConvertOptions options)
08:12:31    bei MailClient.Schedule.Event.EventComposer…ctor(Calendar calendarObject, Event clonedComponent, IEvent parentItem, Boolean removeMethod)
08:12:31    bei MailClient.Protocols.CalDav.Synchronizer.EventItemSynchronizer.CreateItem(Folder folder, Component payloadComponent, Uri uri, String eTag, CancellationToken cancellationToken)
08:12:31    bei MailClient.Protocols.CalDav.Synchronizer.SynchronizeItemsCommand.CreateCalDavItem(Stream payloadStream, Encoding encoding, Uri uri, String eTag)
08:12:31    bei MailClient.Protocols.CalDav.Synchronizer.SynchronizeItemsCommand.CreateCalDavItem(ResponseItem item)
08:12:31    bei MailClient.Protocols.CalDav.Synchronizer.SynchronizeItemsCommand.DownloadItemsMultiget(IList1 uris, Boolean calDav) 08:12:31    bei MailClient.Protocols.CalDav.Synchronizer.SynchronizeItemsCommand.DownloadCalDavItems(IList1 uris)
08:12:31    bei MailClient.Protocols.CalDav.Synchronizer.SynchronizeItemsCommand.ProcessItems(Dictionary`2 items, Boolean deltaSyncReport)
08:12:31    bei MailClient.Protocols.CalDav.Synchronizer.SynchronizeItemsCommand.Execute(WorkerStatus status)
08:12:31    bei MailClient.Commands.Command.Process(WorkerStatus status)