Help with getting Invoke-SwisVerb ExecuteScript working in powershell

Can anyone provide some details on what Invoke-SwisVerb is looking for:

Invoke-SwisVerb -SwisConnection $SwisConn -EntityName Cirrus.ConfigArchive -Verb ExecuteScript ($NCMID, $TestScript, "admin")

I have tried $NCMID with and without ' in it, but same results.

PS W:\> $NCMID

'c51a6a39-25aa-4ce1-8884-ff181f194746'

PS W:\> $TestScript

show clock

Get the following response:

Invoke-SwisVerb : Verb Cirrus.ConfigArchive.ExecuteScript cannot unpackage parameter 0 of type System.Guid[]

At line:1 char:1

+ Invoke-SwisVerb -SwisConnection $SwisConn -EntityName Cirrus.ConfigAr ...

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    + CategoryInfo          : InvalidOperation: (:) [Invoke-SwisVerb], FaultException`1

    + FullyQualifiedErrorId : SwisError,SwisPowerShell.InvokeSwisVerb