cannot complete this function

Question

Hello Team!

When I tried to add the client machine to the domain after restoring the Windows Server 2012 R2 domain controller,

I encountered the following problem.

"The domain cannot complete this function. The following error occurred while trying to join the domain."

Please assist me in finding a solution to this problem.

Thanks

Tiji

Answer 1

Hi tijithomas,

The error message "The domain cannot complete this function" while trying to add a client machine to the domain after restoring a Windows Server 2012 R2 domain controller could be due to network connectivity or DNS configuration issues. Ensure the client can communicate with the domain controller and that DNS settings are correct. Also, check time synchronization, firewall settings, and security software that might be blocking communication. Verify the health of the domain controller, DNS records, and network configurations on both machines. Use proper administrative credentials and permissions. If the problem persists, consider disjoining and rejoining the client machine to the domain, and confirm that necessary server roles and services are installed and running on the domain controller.

Hope this helps.

Thanks,

Answer 2

Hello tijithomas,

Thank you for posting in Microsoft Community forum.

Hope the information provided by Mr. Trust_A is helpful to you.

Here are my suggestions for your reference.

1.How did you restore your Domain Controller?
Recommend way is to use Windows built-in back up tool to perform backup operation and restore operation on Domain Controller.

2.How many DCs are there in your Domain?
Do you have the only one Windows Server 2012 R2 domain controller, then you restored it? Or you have more than one DC (Windows Server 2012 R2 domain controller), then you restore this DC into domain?

If you have only this one Windows Server 2012 R2 domain controller, then you restored it, you should check if this DC itself work fine or not. You can run Dcdiag /v on this DC to check the result.

If you have more than one DC, you should not only check DC function itself on each DC, but also check the AD replication between all DCs in the domain.

repadmin /showrepl >c:\repsum1.txt

repadmin /replsum >c:\repsum2.txt

repadmin /showrepl * /csv >c:\repsum.csv

3.You can also check the AD ports on both AD and clients.

Active Directory and Active Directory Domain Services Port Requirements

https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/dd772723(v=ws.10)?redirectedfrom=MSDN

Active Directory Replication over Firewalls

https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/bb727063(v=technet.10)?redirectedfrom=MSDN

Hope the information above is helpful. If you have any question or concern, please feel free to let us know.

4.What DNS server did you configure as Preferred DNS server on this client?
If you set IP address of this restored DC as Preferred DNS server on this client (assume it is also a DNS server), you can change IP of another DNS server as Preferred DNS server on this client, and then check if you can join domain.

Hoe the information above is helpful. If you have any question or concern, please feel free to let us know.

Best Regards,
Daisy Zhou