1203 The directory service could not replicate the following object from the source directory service at the following network address because of an Active Directory Domain Services schema mismatch.

Question

While promoting 2016 domain controller promotion showed success and server restarted. After restart when i logged in and checked dcpromo logs showed Active Directory Domain services will attempt to synchronize the schema before attempting to synchronize the following directory partition DC=xyz, DC=com. FSMO role holder is still a 2012 R2 server with FFL and DFL at 2008R2 and all 2012R2 domain controller has migrated to dfsrstate eliminated. kindly let me know if anyone has come across such scenario.

Answer 1

Hi Patrick/Daisy,

I have gone through the uRL - https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/schema-mismatch-error-ad-installation-wizard-dcpromo

I have DC1 and DC2 running on 2012R2 - I promoted a new DC 2016 and everything went fine after promotion server restarted and when I logged in and checked dcpromo.log said Warning NTDS replication / Replication : 1203
The directory service could not replicate the following object from the source directory service at the following network address because of an Active Directory Domain Services schema mismatch.
object:
CN=Tom,OU=test,DC=abc,DC=com.

I also saw event ID 1450 on my PDC for the same object

I didnt see any error while promoting my new 2016 DC. But on my new 2016 DC I see the below events.
Directory service Error event ID 1791 and Warning event ID 1203 referencing the same object.
DNS server Warning event ID 4013

I found the same issue description from this URL - https://blog.markdepalma.com/?p=59

Above URL is asking to reset ACL.

Kindly suggest can I go ahead with this approach.

Regards,
Ankit

Answer 2

Something here may help.
https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/schema-mismatch-error-ad-installation-wizard-dcpromo

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Answer 3

Hello @Ankit Patel ,

Thank you for posting here.

Based on the description "The directory service could not replicate the following object from the source directory service at the following network address because of an Active Directory Domain Services schema mismatch.", do you know the error message occurs between which two DCs (source DC and target DC)?

We can check AD replication status in the AD forest by running commands below on PDC.

repadmin /showrepl >c:\repsum1.txt

repadmin /replsum >c:\repsum2.txt

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

If there is no any error message in all the result, it means AD replication works fine.

Hope the information above is helpful.

Should you have any question or concern, please feel free to let us know.

Best Regards,
Daisy Zhou

Answer 4

Might work through this one.
https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/replication-error-8418

--please don't forget to Accept as answer if the reply is helpful--