When browsing the exchange plugin through the Virtual client exchange databases are not displayed.
Check DAG name in exchange management console, mailbox, database availability groups and is it different to the DAG name being displayed under the NetVault virtual client.
Checked DNS found that cluster IPaddress had two different names against it and that the incorrect name appearing in NetVault was one of them.
Incorrect DNS entry supplying the wrong DAG name causing the PowerShell script that collects the database information to fail.
1/ Remove incorrect DNS entry from DNS server and allow time for the changes to proper gate to all other DNS servers.
2/Remove virtual client in client management
3/ Uninstall Exchange API on all exchange clients
4/ Create Virtual client again using IPaddress
5/In backup window configure then browse virtual client
