Windows dns an unknown error occurred while validating the server
Use -ignorelastdcindomainmismatch to override if this is truly the last domain controller and there is phantom domain controller metadata You cannot promote this domain controller, as it is also a RDS server configured for more than two admin users.Without Gpprep, you cannot use RSOP Planning across domains.Run /gpprep manually for all domains that were not previously prepared for Windows Server 2003, Windows Server 2008, or Windows Server 2008 R2.The Install-From-Media promotion of a Read-Only DC cannot start because the specified source database is not allowed. Install If selecting (or not selecting) the Server Manager option Restart each destination server automatically if required whendemoting a domain controller through role removal, the server always restarts, regardless of choice.Only databases from other RODCs can be used for IFM promotion of a RODC. When attempting to promote a Windows Server 2012 domain controller into an existing Windows Server 2003, Windows Server 2008, or Windows Server 2008 R2 forest, prerequisite check fails with error: Code - Verification of prerequisites for AD prep failed.
To see the code at the end of a domain controller configuration, you have several options: You cannot demote this domain controller, as it is also a Certification Authority.