Hello @Marco Tse ,
During the readiness check for the Cumulative Update, validation failed because some required Resource Providers (RPs) particularly Microsoft.Attestation are not registered in the subscription. Registering these RPs is mandatory for Azure Local and Azure Arc deployments, and this requirement is now enforced to ensure the environment meets compliance prerequisites before updates can proceed.
As outlined in the Azure Local Arc prerequisites, specific resource providers must be registered for Azure Local deployments. In this case, the Microsoft.Attestation RP appears to be missing, and the environment checker now requires it to be registered before allowing updates.
Check the registration state of Microsoft.Attestation-
Connect-AzAccount -SubscriptionId $Subscription -TenantId $Tenant -DeviceCode
Get-AzResourceProvider -ProviderNamespace "Microsoft.Attestation"
Register the missing resource provider by running (requires Owner or Contributor subscription role):
Register-AzResourceProvider -ProviderNamespace "Microsoft.Attestation"
Hope this helps! Please let me know if you have any queries.