I have two identical servers running Exchange 2013SP1 on Server 2012R2.  When trying to run CU8, one runs through the prerequisites fine, the other has these errors. What am I doing wrong?  Why does the update not see the mailbox server role?

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.UnifiedMessagingRoleNotInstalled.aspx

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 (12296) 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:
The Active Directory schema isn't up-to-date, and this user account isn't a member of the 'Schema Admins' and/or 'Enterprise Admins' groups.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.SchemaUpdateRequired.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:
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:
You must use an account that's a member of the Organization Management role group to install the first Mailbox server role in the topology.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.DelegatedUnifiedMessagingFirstInstall.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 watermill and site Default-First-Site-Name, 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 2003 native or later. To install Exchange Server 2013, the forest functional level must be at least Windows Server 2003 native.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.ForestLevelNotWin2003Native.aspx

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.MailboxRoleNotInstalled.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 2013 by using 'Setup /PrepareAD'. No Exchange 2007 server roles have been detected in this topology. After this operation, you will not be able to install any Exchange 2007 servers.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.NoE12ServerWarning.aspx

Warning:
Setup will prepare the organization for Exchange 2013 by using 'Setup /PrepareAD'. No Exchange 2010 server roles have been detected in this topology. After this operation, you will not be able to install any Exchange 2010 servers.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.NoE14ServerWarning.aspx

Based on the messages regarding the AD and Schema stuff, I'm wondering if these machines are in the same Domain (if different child domains or different domains make sure you run the schema, ad, and domain prep stuff). Also make sure hte account you are using to install the CU is an Org Admin.  Also, just as a sanity check make sure allthe Exchange related groups exist int he Domain.

Hi Rust,

Thank you for your question.

I agree with Hite.

In addition, we should make sure Exchange could ping DC without any problems, the AD replication is no problem.

Then we could prepare AD on DC by the following link.

https://technet.microsoft.com/en-us/library/bb125224(v=exchg.150).aspx

then run the setup on Exchange server to check if the issue persist.

We could also refer to the following link to update Exchange CU8:

https://technet.microsoft.com/en-us/library/jj983803(v=exchg.150).aspx

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim