After a successful Exchange 2013 migration, the old exchange 2010 object was left behind. When opening Exchange 2013 EAC under the “Servers” option, “Servers” tab, you can see it listed as a “provisioned server”.
For some reason this is not removed from AD automatically when Exchange 2010 is uninstalled from the server, so you need to remove it manually.
Using ADSIEdit, open the “Configuration” node, then “CN=Services”, then “CN=Microsoft Exchange” then “CN=<organisation name>”, then “CN=Administrative Groups”, then “CN=Exchange Administrative Group (FYDIBOHF23SPDLT)”, then “CN=Servers” under this you’ll see the nodes for each Exchange server including the old 2010 server(s).
Delete the node for the old Exchange 2010 server(s).
Open up EAC, refresh and you’ll see the object has gone.