Thanks Dave. It looks like it is an issue running get-command rather than an issue running get-dscresource. I’ve only recently upgraded to v4. I do have SQL Server on this machine, which may have some bearing on this.
PS C:\Program Files\WindowsPowerShell\Modules> get-command
get-command : Object reference not set to an instance of an object.
At line:1 char:1
+ get-command
+ ~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Get-Command], NullReferenceException
+ FullyQualifiedErrorId : System.NullReferenceException,Microsoft.PowerShell.Commands.GetCommandCommand