I have a 2008 domain and I'm trying to add another DC to it, which is running Windows Server 2012r2
When I try to promote to a DC, it fails on prerequisite check with the following error:
Verification of prerequisites for Active Directory preparation failed. Unable to verify whether schema master has completed a replication cycle after last reboot.
Exception: Unavailable Critical Extension. Server extended error: 8366. Server extended message: 000020AE: SvcErr: DSID-03210384, problem 5010 (UNAVAIL_EXTENSION), data 8610
.
Adprep failed to verify whether schema master has completed a replication cycle after last reboot.
[Status/Consequence]
The schema is not upgraded.
[User Action]
Check the log file ADPrep.log in the C:\Windows\debug\adprep\logs\20151010161101-test directory for possible cause of failure.
I ran adprep manually on my 2008 DC and it said: Domain-wide information has already been updated.
[Status/Consequence]
Adprep did not attempt to rerun this operation.
Can you give us more details about your domain.
How many domain controllers do you have with windows 2008?
Windows 2008 version?
Level of your forest in 2008?
Thank you.
D.