Problem:
During a backup job, a virtual machine is skipped. The associated error message shows that the configuration version is too low.
Solution:
Use the Microsoft’s Hyper-V Manager or PowerShell to upgrade the virtual machine version. See https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/deploy/upgrade-virtual-machine-version-in-hyper-v-on-windows-or-windows-server for additional guidance.