Seem to have hit an error trying this on an HP z620. Can't write the KEK and DBX and met with an error:
Set-SecureBootUefi : Incorrect authentication data: 0xC0000022
At line:1 char:1
+ Set-SecureBootUefi -AppendWrite -Name KEK -ContentFilePath C:\TEMP\co ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : PermissionDenied: (Microsoft.Secur...BootUefiCommand:SetSecureBootUefiCommand) [Set-Secu
reBootUEFI], UnauthorizedAccessException
+ FullyQualifiedErrorId : SetFWVarFailed,Microsoft.SecureBoot.Commands.SetSecureBootUefiCommand
Any idea? Thanks!!!