Hyper-V Virtual Machine cannot be displayed or showed as “saved-critical” in Hyper-V Manager.

Problem
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Hyper-V Virtual Machine cannot be displayed or showed as “saved-critical” in Hyper-V Manager.

Solution
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1. Delete the DC virtual machine manually as it cannot be shutdown/start from hyper-v manager;
2. Create two virtual machine with original VHD disk for DC and Exchange VM;
3. Boot up the DC and Exchange VM, configure the network adapter with correct IP settings.
4. Verify the exchange service and we can receive/send email normally.