Released: July 2021 Exchange Server Security Updates

Hello,

We are using Exchange2013 CU23 on premise and have an hybrid environment.

We updated our ExchangeServers successfully and now we are trying to update our Schema. And there we encountered a problem.

During the prerequisite it failed at 96%. 

CMD/Setup:

Microsoft Exchange Server 2013 Cumulative Update 23 Unattended Setup

Performing Microsoft Exchange Server Prerequisite Check

Prerequisite Analysis FAILED
The On-Premises test failed with the message: Object reference not set to an instance of an object..
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.DidOnPremisesSettingCreatedAnException.aspx

The Exchange Server setup operation didn't complete. More details can be found in ExchangeSetup.log located in the
<SystemDrive>:\ExchangeSetupLogs folder.

error(s) in Exchangesetuplog:

[07-22-2021 07:55:28.0679] [1] Failed [Rule:DidOnPremisesSettingCreatedAnException] [Message:The On-Premises test failed with the message: Object reference not set to an instance of an object..]
[07-22-2021 07:55:28.0679] [1] [REQUIRED] The On-Premises test failed with the message: Object reference not set to an instance of an object..
[07-22-2021 07:55:28.0679] [1] Help URL: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.DidOnPremisesSettingCreatedAnException.aspx

Unfortunally there is no information on the Microsoft site provided in error message.

In the Exchangesetuplog we see also this message:

[07-22-2021 07:55:28.0679] [1] Evaluated [Setting:MicrosoftExchangeSystemObjectsCN] [HasException:True] [Value:
System.DirectoryServices.DirectoryServicesCOMException (0x8007202B): A referral was returned from the server.

at System.DirectoryServices.DirectoryEntry.Bind(Boolean throwIfFail)
at System.DirectoryServices.DirectoryEntry.Bind()
at System.DirectoryServices.DirectoryEntry.get_AdsObject()
at System.DirectoryServices.DirectorySearcher.FindAll(Boolean findMoreThanOne)
at Microsoft.Exchange.Management.Deployment.ADProvider.Run(Boolean useGC, String directoryEntry, String[] listOfPropertiesToCollect, String filter, SearchScope searchScope)
at Microsoft.Exchange.Management.Analysis.PrereqAnalysis.<CreateActiveDirectoryPrereqProperties>b__120(Result`1 x)
at Microsoft.Exchange.Management.Analysis.Builders.SettingBuilder`2.<>c__DisplayClass1.<SetValue>b__0(Result x)
] [ParentValue:"<NULL>"] [Thread:41] [Duration:00:00:46.3759730]
[07-22-2021 07:55:28.0679] [1] Finished [Setting:MicrosoftExchangeSystemObjectsCN] [Duration:00:00:46.3759730]

and this one:

[07-22-2021 07:54:43.0115] [1] Evaluated [Setting:IsHybridObjectFoundOnPremises] [HasException:True] [Value:
Microsoft.Exchange.Management.Deployment.HybridConfigurationDetection.HybridConfigurationDetectionException: The On-Premises test failed with the message: Object reference not set to an instance of an object.. ---> System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.Exchange.Management.Deployment.HybridConfigurationDetection.HybridConfigurationDetection.TestOnPremisesOrgRelationshipDomainsCrossWithAcceptedDomain(IOnPremisesHybridDetectionCmdlets onPremCmdlets)
at Microsoft.Exchange.Management.Deployment.HybridConfigurationDetection.HybridConfigurationDetection.RunOnPremisesHybridTest()
--- End of inner exception stack trace ---
at Microsoft.Exchange.Management.Deployment.HybridConfigurationDetection.HybridConfigurationDetection.RunOnPremisesHybridTest()
at Microsoft.Exchange.Management.Analysis.PrereqAnalysis.<.ctor>b__27(Result`1 x)
at Microsoft.Exchange.Management.Analysis.Builders.SettingBuilder`2.<>c__DisplayClass1.<SetValue>b__0(Result x)
System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.Exchange.Management.Deployment.HybridConfigurationDetection.HybridConfigurationDetection.TestOnPremisesOrgRelationshipDomainsCrossWithAcceptedDomain(IOnPremisesHybridDetectionCmdlets onPremCmdlets)
at Microsoft.Exchange.Management.Deployment.HybridConfigurationDetection.HybridConfigurationDetection.RunOnPremisesHybridTest()
] [ParentValue:"<NULL>"] [Thread:44] [Duration:00:00:00.8437672]
[07-22-2021 07:54:43.0115] [1] Finished [Setting:IsHybridObjectFoundOnPremises] [Duration:00:00:00.8437672]

We need help or information to upgrade our AD schema so we are not vulnerable anymore!