After you upgrade to Cumulative Update 3 for Microsoft Exchange Server 2019 or Cumulative Update 14 for Exchange Server 2016, you receive the following error message:
Log Name: ApplicationSource: MSExchange AutodiscoverDate: DateTimeEvent ID: 1Task Category: WebLevel: ErrorKeywords: ClassicUser: N/AComputer: ComputerNameDescription:Unhandled Exception "Object reference not set to an instance of an object."Stack trace: at Microsoft.Exchange.AutoDiscoverV2.FlightSettingRepository.GetHostNameFromVdir(ADObjectId serverSiteId, String protocol)at Microsoft.Exchange.AutoDiscoverV2.AutoDiscoverV2.ExecuteOnPremEndFlow(AutoDiscoverV2Request request)at Microsoft.Exchange.AutoDiscoverV2.AutoDiscoverV2.Execute(AutoDiscoverV2Request request, ITenantRepository tenantRepository)at Microsoft.Exchange.AutoDiscoverV2.AutoDiscoverV2HandlerBase.<>c__DisplayClass11_0.<ProcessRequest>b__0()at Microsoft.Exchange.Common.IL.ILUtil.DoTryFilterCatch(Action tryDelegate, Func`2 filterDelegate, Action`1 catchDelegate)