Thanks LucD for your reply..

After adding the line as you mentioned getting following error.

New-HardDisk : 23/02/2023 17:35:56 New-HardDisk The operation for the entity "xcpXXXXX" failed with the following message: "A general system error occurred: PBM error occurred
during PreReconfigureCallback: Fault cause: vmodl.fault.SystemError
;
"
At C:\temp\test.ps1:4 char:22
+ Get-VM -Name $vm | New-HardDisk -CapacityGB 10
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [New-HardDisk], SystemError
+ FullyQualifiedErrorId : Client20_TaskServiceImpl_CheckServerSideTaskUpdates_OperationFailed,VMware.VimAutomation.ViCore.Cmdlets.Commands.VirtualDevice.NewHardDisk

Regards,

Kumar