Error when accessing web service with ISHRemote

I am trying to start a Content Manager web service session with a command like this:

$ishSession = New-IshSession -WsBaseUrl -PSCredential

This command fails with the following error:

New-IshSession : The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for
communication because it is in the Faulted state.
At line:1 char:15
+ ... shSession = New-IshSession -WsBaseUrl intraloxdevcm02.sdlprod ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [New-IshSession], CommunicationObjectFaultedException
    + FullyQualifiedErrorId : NewIshSession,Trisoft.ISHRemote.Cmdlets.Session.NewIshSession

Any ideas how I could fix this?