Upgrading from Exchange 2010 SP1 to SP2 on CAS servers

Here, we are trying to install SP2 on our corporate servers, and started to run into trouble:  IIS 6 WMI Compatibilty error on clients access role section during setup.

But first, let's recall and remember new extra features that comes with Exchange 2010:

Hybrid Configuration Wizard. Provides integration between both on-premise and the cloud-based mailboxes.

Address book policies. Permit on a simple way create address book policies to filtering which GAL, room list, address list or offline address book are readable for different users.

Cross-site silent redirection. This feature redirect the user to other CAS server if the client request is better server by other CAS server.

Mailbox replication service. Two new parameters have been added to the new-WebServicesVirtualDirectory and Set-WebServicesVirtualDirectory cmdlets to remove the manual configuration when moving mailboxes to another forest.

Mailbox auto-mapping. Permit dissable automapping on selected mailboxes using Add-MailboxPermission cmdlets.

Multivalue custom attributes. Five new multivalue custom attributes to add extra information.

Litigation hold. Using IgnoreLegalHold cmdlet permit to administrators bypass this condition.

Outlook Web App Mini. Similar to the Outlook Mobile Access client from Exchange 2003, is designed for mobile operating systems, without adding extra images or features. Simply manages email. And maybe this new feature would be the cause of this error.

With this upgrade, to use some of the above features, IIS6 WMI compatibility is needed in client access servers, but in older versions this was not required. So, to correct the isssue during setup, simply run those commands on a powershell :

Import-Module ServerManager

Add-WindowsFeature NET-Framework, NET-HTTP-Activation, Web-Server, Web-Basic-Auth, Web-Windows-Auth, Web-Metabase, Web-Net-Ext, WAS-Process-Model, Web-Lgcy-Mgmt-Console, RSAT-Web-Server,  RSAT-ADDS, Web-ISAPI-Ext, Web-Digest-Auth, Web-Dyn-Compression, Web-WMI, RPC-Over-HTTP-Proxy –Restart

Or add using GDI:

Control panel, got to programs and features, click on turn windows features on or off, expand roles, select web server (IIS), click on add role services and mark in group "IIS 6 Management compatibiliy" this subcomponents: IIS 6 WMI Compatibilty.