Windows 2008R2 sysprep Error [msoobe.exe] Failed to install product key

In the System control panel window, ("control system" at cmd), under Windows Activation there's a link: "3 days until automatic activation. Activate Windows now." Online Activation succeeds, both automatically (at first login after 3 days) or manually via the link in Computer Properties. So the product  key would seem to be valid. Besides the logged error message, I've found nothing visibly wrong. (Maybe product key installation attempts time out, causing sysprep to be slower than it should be - but I have no good basis for comparison on this OS.)

Seen this before? Cause for concern? Solutions?

My familiarity with Windows licensing is mostly second-hand, but I know 2 thrilling acronyms that apply to us: SPLA and MAK; and one acronym that does not: KMS.

Get-OSCustomizationSpec -Name specName | New-OSCustomizationSpec -Name tempSpecName -type NonPersistent
set-OScustomizationSpec tempSpecName -adminPassword $adminPwd -namingScheme Fixed -namingPrefix $dnsName -domain $domain -domainCredentials $creds -autoLogonCount 1
$clone = New-VM -vm $sourceVM -name $vmName -OSCustomizationSpec tempSpecName -VMHost $vmhost -location $destFolder -Datastore $datastore -diskStorageFormat Thin
start-vm $clone

In our spec, ChangeSID is True. Domain join succeeds, so network connectivity would seem to be in place there, at least.