Exchange Update Failed  KB ID 0001923 Problem While attempting to install an Exchange CU update, (CU15 for Exchange 2019), I got this error. Error: The following error was generated when “$error.Clear(); # # O15# 2844081 – Create PartnerApplication “Exchange Online” in DC and On-Premise # $exch = [Microsoft.Exchange.Data.Directory.SystemConfiguration.WellknownPartnerApplicationIdentifiers]::Exchange; $exchApp = Get-PartnerApplication $exch -ErrorAction SilentlyContinue -DomainController $RoleDomainController | Where { $_.UseAuthServer } | Where {...