Exchange 2007 SP3 install failing on an active/passive cluster

Hi,

• I have an active/passive cluster and I’ve followed the MS instructions.
• I’ve upgraded the passive node using the setup /m:upgrade command and that completed without any problems.
• I then move the cluster over to the recently upgraded node and brought the CMS service online.
• When I then run the setup /upgradecms command it fails with the following error

The following server roles will be upgraded

    Clustered Mailbox Server

Performing Microsoft Exchange Server Prerequisite Check

Configuring Microsoft Exchange Server

An unexpected error has occurred and debug information is being generated: Object reference not set  to an instance of an object.

     Object reference not set to an instance of an object.

Exchange Server setup encountered an error.

Any help would be greatly appreciated.

Thanks,

Nige