Now in public preview: Ephemeral OS disk support on Azure Virtual Desktop

Did do try it out, but got the following error message:

{
  "ActivityId": "xxxxxx-xxxxx-xxxxxxx-xxxxx-xxxx",
  "ErrorDetails": [
    {
      "faultCode": "UncategorizedVmProvisionFailureException",
      "faultText": "VM /subscriptions/xxxxxx-xxxxx-xxxxxxx-xxxxx-xxxx/resourceGroups/rg-avd-002c-prod/providers/Microsoft.Compute/virtualMachines/AC-P2C-0 has failed to provision.  Internal error code:  NotSupported.  Internal error message:  VMs and VM Scale Set Instances using an ephemeral OS disk support only Readonly caching.",
      "faultContext": "UpdateSessionHost",
      "faultType": 1
    }
  ]
}