KB5077181 - Hyper-V VM launch failure - key protector could not be unwrapped

Question

HostGuardianService-Client Event log: Appears to start out OK at Event 1018 (bottom) but fails at Event 2006.

Event ID	Decscription
2014	The Host Guardian Service Client failed to unwrap a Key Protector on behalf of a calling process. This event will normally correspond to a failure to startup a shielded virtual machine. Consult the description for further details. This could be related to an attestation issue, a Key Protection Server issue, or a network connectivity issue:
2006	Failed to roll the transport key: The certificates parameter is empty.
2002	Successfully opened Shielded VM Local Certificates store.
2009	Initiating unwrap of key protector.
1003	Remote attestation completed.
1018	Remote attestation succeeded and returned a health certificate with the thumbprint 69246C6BDE4F9BC5CC147C59BFCA792A18483B58.

Plz advise...

Answer 1

Thank you, tocguy. Let us try something else. From the Microsoft's support document

https://learn.microsoft.com/en-us/troubleshoot/windows-server/virtualization/troubleshoot-guarded-hosts

In the Windows search, 

Type cmd, right-click it, and choose Run as Administrator.

reg add HKLM\SOFTWARE\Microsoft\.NETFramework\v4.0.30319 /v SystemDefaultTlsVersions /t REG_DWORD /d 1 /f /reg:64
reg add HKLM\SOFTWARE\Microsoft\.NETFramework\v4.0.30319 /v SystemDefaultTlsVersions /t REG_DWORD /d 1 /f /reg:32

I’m eager to hear back and work together to find a solution.

Answer 2

Hi,

Does uninstalling the Update help to resolve the problem?

To remove the most recent update, please follow these steps to access the Windows Recovery environment:

1. Open the Settings app by pressing the Win + I keys.
2. Navigate to System > Recovery.
3. Click the ""Restart Now"" button next to Advanced Startup.
4. Choose the Troubleshoot option.
5. Select ""Uninstall Updates,"" then choose either ""Uninstall Latest Quality Update"" or ""Uninstall Latest Cumulative Update.""

Allow the process to complete.

I’m eager to hear back and work together to find a solution.