You cannot run the Test-ExchangeSearch cmdlet without parameters or run it together with the -MailboxDatabase parameter in a Microsoft Exchange Server 2016 or Microsoft Exchange Server 2013 Cumulative Update 6 (CU6) environment. However, you can run Test-ExchangeSearch together with other parameters successfully.
This issue occurs because the names of the Health mailboxes in Microsoft Exchange Server 2016 and Microsoft Exchange Server 2013 CU6 are changed.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 3115610 - Last Review: Mar 30, 2016 - Revision: 1
Exchange Server 2016 Enterprise Edition, Exchange Server 2016 Standard Edition, Exchange Server 2013 Enterprise, Exchange Server 2013 Standard Edition