I have a Windows 2012R2 DC that I am trying to prep to add two Windows 2016 servers to. After completion, I will then upgrade the 2012R2 DC. The 2012R2 is the production machine so don't want to too much to it since it has all the user accounts currently. I am using the admin account that is member of Schema, Enterprise, and Domain Admin groups. I have run DCDIAG and all tests pass so health is good. I have two DNS servers, the 2012R2 and one of the 2016 servers. DNS is setup for secure updates only.
When I run the /forestprep I am getting the following errors:
Adprep was unable to create the object CN=AuthN Policies,CN=AuthN Policy Configuration,CN=Services,CN=Configuration,DC=local,DC=gscsda,DC=org in Active Directory Domain Services.[Status/Consequence]
This Adprep operation failed.
[User Action]
Check the log file ADPrep.log in the C:\Windows\debug\adprep\logs\20190321073420
directory for more information. Restart Adprep.
Adprep encountered an LDAP error.
Error code: 0x10. Server extended error code: 0x57, Server error message: 00000057: LdapErr: DSID-0C090E21, comment: Error in attribute conversion operation, data 0, v2580
Adprep was unable to update forest information.
[Status/Consequence]
Adprep requires access to existing forest-wide information from the schema master in order to complete this operation.
[User Action]
Check the log file, ADPrep.log, in the C:\Windows\debug\adprep\logs\20190321073420 directory for more information.
