While Configuring an Active Directory in the agent, you may encounter the following error on the WSTEP tab of the on-premises PKIaaS Virtual Machine.  

See below for a list of possible causes and the corresponding solutions.

Orphaned Domain Controller

The <DOMAIN-CONTROLLER> Domain Controller mentioned in the error might be orphaned. This might occur if the Domain Controller was accidentally or incorrrectly removed from an Active Directory forest.

Issue resolution: Remove the orphaned Domain Controller as explained in https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/remove-orphaned-domains

Missing DNS record

The DNS server running on <DNS-RESOLVER-IP-ADDRESS>:53 does not have a DNS Record for <DOMAIN-CONTROLLER>. This error might occur after following the Microsoft documentation to solve the orphaned Domain Controller issue mentioned above.

Issue resolution: Adding the missing DNS record.