Hi,
Did you check the VM settings? Are all drives available to the VM? You might have something (VHDX or iso) attached to the VM, which is no longer available.
https://www.leedesmond.com/2016/01/hyper-v-new-vm-error-0x80070003/
You can try creating a new VM and attach VHDX to it. In addition, you can contact our support team on our forum:
https://forums.starwindsoftware.com/
Cheers,
Alex Bykovskyi
StarWind Software
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