What is causing the error when migrating from WinServer 2003 to WinServer 2012?

Question

Domain Name System

Migration from WinServer 2003 to WinServer 2012 was done according to this instruction - https://habrahabr.ru/company/microsoft/blog/245667/
At the stage of adding a new domain controller to an existing domain, an error occurred with the following content: "Replica check failed. Failed contact the Active Directory domain controller for domain 'nameDomen'. Make sure the DNS domain name is entered correctly."
What could be the problem?
PS I'm a noob

Answer 1

How many domain controllers do you have on the network?
Roles transferred to the second server?

Answer 2

Raise a clean 2012 server, make it a secondary domain controller, then transfer all 5 FSMO roles to it, reconfigure the DNS server for clients, because your clients will access DNS which is on the first server (if it is not separate of course, which I doubt) for this in DHCP server, change the DNS server address to a new one from Windows 2012, if there is no DHCP then handles in the interface properties on each client, then delete the 2003 controller, after checking that all roles are on the new server, after deleting we extinguish the 2003 machine, we increase the level of blood pressure to 2012