As the process begins in removing Exchange 2010 from an environment, you might run into an issue where the server has Offline Address Books on it even though everything else has been moved off.
The error you see below is quickly resolved by moving the Offline Address Books to another server:
Now launch the Exchange Management Shell (EMS) and run the following command for the server:
- Get-OfflineAddressBook -Server MailboxServer1 | Move-OfflineAddressBook -Server MailboxServer2 -Confirm:$all
Depending on the number of address books you have, this process can take a few minutes.
Once done, you can run the first part of the command to check if there are still Offline Address Books on the server. When nothing is coming up in the command, head back to your uninstall and click Retry and it should allow you uninstall now.
Happy Uninstalling Exchange Server 2010.