If you get the following error while Measure-VM in Hyper-V Resource Metering:
Measure-VM : Object reference not set to an instance of an object.
+ CategoryInfo : NotSpecified: (:) [Measure-VM], NullReferenceException
+ FullyQualifiedErrorId : Unspecified,Microsoft.HyperV.PowerShell.Commands.MeasureVMCommand
Check if there are hard disks for the VM that have no paths in the config. In my case there was a couple of disks like this that caused the issue.