When this issue occurs, the following exception information is logged in the ActiveSync log:
SyncCommand_GenerateResponsesXmlNode_AddChange_Exception :
Microsoft.Exchange.Data.Storage.PropertyErrorException: Property: [{00062008-0000-0000-c000-000000000046}:0x8501] ReminderMinutesBeforeStartInternal, PropertyErrorCode: NotFound, PropertyErrorDescription: .
at Microsoft.Exchange.Data.Storage.PropertyBag.ThrowIfPropertyError(StorePropertyDefinition propertyDefinition, Object propertyValue)
at Microsoft.Exchange.Data.Storage.StoreObject.GetProperty(PropertyDefinition propertyDefinition)
at Microsoft.Exchange.Data.Storage.MeetingMessage.get_Item(PropertyDefinition propertyDefinition)
at Microsoft.Exchange.AirSync.SchemaConverter.XSO.XsoMeetingRequestProperty.get_NestedData()
at Microsoft.Exchange.AirSync.SchemaConverter.AirSync.AirSyncMeetingRequestProperty.InternalCopyFrom(IProperty srcProperty)
at Microsoft.Exchange.AirSync.SchemaConverter.AirSync.AirSyncProperty.CopyFrom(IProperty srcProperty)
at Microsoft.Exchange.AirSync.SchemaConverter.AirSync.AirSyncDataObject.CopyFrom(IProperty srcRootProperty)
at Microsoft.Exchange.AirSync.SyncCollection.ConvertServerToClientObject(ISyncItem syncItem, XmlNode airSyncParentNode, SyncOperation changeObject, GlobalInfo globalInfo)
at Microsoft.Exchange.AirSync.SyncCollection.<>c__DisplayClassd.b__4(SyncOperation changeObject)