WMI Error. Not Enough Permissions (code 1916)

Situation

A Hyper-V backup plan terminates with the following error: WMI Error. Not Enough Permissions

Cause

The occurrence of this error means that WMI returned the 'not enough permissions' error (WMI code 32774).

WMI (Windows Management Instrumentation) is a set of extensions to the Windows Driver Model that provides an operating system interface through which instrumented components provide information and notification.

Solution

Note that the error occurs when NT Virtual Machine(s) are not allowed to Log on As a Service. This can be fixed by creating a Windows group policy object (GPO) with appropriate settings.

If the error persists, recreate VMs: delete failed VMs, but avoid deleting not their disks (.vhdxs) files.

Create new VMs from scratch, then attach .vhdx disks from original VMs to the created VMs.

Run an elevated PowerShell and execute:

Get-VM | Format-List Name, ID

Find the name of the VM that produced the error to keep its ID to use further.

As the ID is found, get back to PowerShell and run the following command:

Icacls "[path_to_virtual_machine_xml_files]\[VM_ID].xml" /grant "NT VIRTUAL MACHINE[VM_ID]:(OI)F"

where:

• path_t-virtual_machine_xml_files is a path to the Hyper-V VM files (example: C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines)
• VM_OD is a virtual machine ID