Errors on the Domain Controller how to fix?

Question

Windows Server

Actually, the main CD + backup CD worked in conjunction, but we decided to turn off the backup CD for some time, after 3 days, partly for the people when they entered their account, it gave out: "A trust relationship with the controller has not been established ..." I had to display from the domain and start again.
"srv_vr$" is a backup controller
And the other day, on the main CD, errors began to pour in the control panel next. type:
1)"The Kerberos client received a KRB_AP_ERR_MODIFIED error from the srv_vr$ server. This means that the target server was unable to decrypt the ticket provided by the client. This is possible when the target SPN is registered to an account other than the account used by the target service. Ensure that the target SPN is only registered to the account used by the server.This error can also occur if the target service's password differs from the password set for it in the Kerberos Key Distribution Center.Make sure that the passwords in the service on the server and in the key distributions match If the server name is incomplete and the destination domain (srv.local) is different from the client domain (srv.local),check these two domains for server accounts with the same name, or use the fully qualified name to identify the server."
2)NETLOGON When establishing a session from the srv_vr computer, name confirmation was not received. The security database contains links to srv_vr$ accounts. Error:
Access denied.
well, errors like that are pouring in 8-10 times a day, who has come across, where to look?

Answer 1

but decided to turn off the backup CD for a while

standing ovation! If you decide to get rid of the backup domain controller, then demote from domain controller is first done to it. So that AD does not look for it and the entire load goes to the PDC.
The second point, you would specify at least the version of Windows Server.
What to do? Raise the BDC, remove it from the domain and then observe the development of events. Or hand shoveling in the AD editor, but I would not advise you to do this.