Exchange 2013 - error running new-autodiscovervirtualdirectory

Exchange 2013 Version 15.0 (Build 620.29) 

I start a powershell session as administrator. When I run: new-autodicovervirtualdirectory

I get this error:

Argument: -Role ClientAccess
    + CategoryInfo          : InvalidArgument: (:) [New-AutodiscoverVirtualDirectory], ArgumentException
    + FullyQualifiedErrorId : DD8AF47F,Microsoft.Exchange.Management.SystemConfigurationTasks.NewAutodiscoverVirtualDi
   rectory
    + PSComputerName        : cccas.ccdomain.local

Running this same command on the test Exchange 2013 server I have, it creates the cirtual directory as it should.

I cannot determine what this error is and how to resolve it. Any help would be appreciated.

Thanks,

                Mark