Get-VMStartPolicy : 4/06/2015 9:53:22 a.m. Get-VMStartPolicy Requested value 'systemDefault' was not found.At line:1 char:40+ foreach ($vm in $vms){get-vmstartpolicy <<<< -vm VM} + CategoryInfo : NotSpecified: (:) [Get-VMStartPolicy], VimException + FullyQualifiedErrorId : Core_BaseCmdlet_UnknownError,
So it turns out after logging this with VMware that it is a known bug and has the Bug ID 1336800. This is set to be fixed in the next release of PowerCLI