Exchange 2019 CU7 Update klappt nicht in Forest-Umgebung

Moin,

ich versuche gerade einen Exchange 2019 von CU5 auf CU7 zu aktualisieren was leider nicht funktioniert und schon über die Prüfung nicht hinausgeht.

Folgende Umgebung habe ich:

Es gibt 2 DCs in der Domäne contoso.com und 2DCs in der Unterdomäne sub.contoso.com. Der Exchange selber ist teil der Domäne sub.contoso.com.

Ich habe es bereits mit den Domänen Administrator aus beiden Domänen probiert. Leider ohne Erfolg.

Error:
The Mailbox server role isn't installed on this computer.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.BridgeheadRoleNotInstalled.aspx

Error:
Setup can't continue with the upgrade because the powershell (23104) has open files. Close the process, and then restart Setup.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.ProcessNeedsToBeClosedOnUpgrade.aspx

Error:
Global updates need to be made to Active Directory, and this user account isn't a member of the 'Enterprise Admins' group.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.GlobalUpdateRequired.aspx

Error:
The local domain needs to be updated. You must be a member of the 'Domain Admins' group and 'Organization Management' role group, or 'Enterprise Admins' group to continue.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.LocalDomainPrep.aspx

Error:
You must be a member of the 'Organization Management' role group or a member of the 'Enterprise Admins' group to continue.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.GlobalServerInstall.aspx

Error:
You must use an account that's a member of the Organization Management role group to install or upgrade the first Mailbox server role in the topology.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.DelegatedBridgeheadFirstInstall.aspx

Error:
You must use an account that's a member of the Organization Management role group to install the first Client Access server role in the topology.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.DelegatedCafeFirstInstall.aspx

Error:
You must use an account that's a member of the Organization Management role group to install the first Client Access server role in the topology.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.DelegatedFrontendTransportFirstInstall.aspx

Error:
You must use an account that's a member of the Organization Management role group to install or upgrade the first Mailbox server role in the topology.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.DelegatedMailboxFirstInstall.aspx

Error:
You must use an account that's a member of the Organization Management role group to install or upgrade the first Client Access server role in the topology.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.DelegatedClientAccessFirstInstall.aspx

Error:
Setup encountered a problem while validating the state of Active Directory: Exchange organization-level objects have not been created, and setup cannot create them because the local computer is not in the same domain and site as the schema master. Run setup with the /prepareAD parameter on a computer in the domain xxx and site XXX, and wait for replication to complete. See the Exchange setup log for more information on this error.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.AdInitErrorRule.aspx

Error:
The forest functional level of the current Active Directory forest is not Windows Server 2012 R2 or later. To install Exchange Server 2019, the forest functional level must be at least Windows Server 2012 R2.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.ForestLevelNotWin2012R2.aspx

Error:
Either Active Directory doesn't exist, or it can't be contacted.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.CannotAccessAD.aspx

Warning:
Setup will prepare the organization for Exchange Server 2019 by using 'Setup /PrepareAD'. No Exchange Server 2016 roles have been detected in this topology. After this operation, you will not be able to install any Exchange Server 2016 roles.
For more information, visit: https://docs.microsoft.com/Exchange/plan-and-deploy/deployment-ref/readiness-checks?view=exchserver-2019

Warning:
Setup will prepare the organization for Exchange Server 2019 by using 'Setup /PrepareAD'. No Exchange Server 2013 roles have been detected in this topology. After this operation, you will not be able to install any Exchange Server 2013 roles.
For more information, visit: https://docs.microsoft.com/Exchange/plan-and-deploy/deployment-ref/readiness-checks?view=exchserver-2019

Habt ihr ne Idee was hier krum sein könnte bzw. was ich prüfen kann?

Gruß

Frank