"unable to set guest customization status in vmx"

That is an unusual error, it likely is related to the vCenter service account or possibly the Instant Clone domain account. 

1. vCenter Service Account - Did you create a custom vsphere role or give a default role like 'Administrator'?
   
   
2. Instant Clone domain account
   1. Power on the Parent Image
   2. Verify that the same portgroup as the pool is assigned. 
   3. From your computer, create an AD computer object  of the same name as the parent in the assigned OU in the pool.
   4. On the Parent Image, attempt to join to the domain using the Instant Clone domain account. 

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