I am trying to decommission an Exchange Server 2007 after a migration to Exchange 2013. While attempting to uninstall the Mailbox Role from Exchange 2007 from "Add/Remove Programs" it is failing with error: This Mailbox server is responsible for generating an Offline Address Book. Removal of the mailbox role is not permitted.
I'm not sure if the 2007 OAB data was actually migrated to 2013. I used ADSI edit to remove the 2007 Public Folder Database, so that data migration might not be possible at this point. Is that likely to cause problems?
What is the best next step to allow the uninstallation of 2007? Are there any Powershell commands to remove the OAB from 2007?