I have an AD environment with 8 ADC running 2008 R2, 1 ADC running 2012 R2. The root DC is running 2008 R2. We are functional level 2003.
We need to upgrade the base OS in phase manner and eventually get rid of all the older version.
We have installed a new ADC on OS 2016 Std, and facing issue in replication. Below is the error:
Replication of application directory partition DC=xxx,DC=com from source <xxxxxxx>) has been aborted. Replication requires consistent schema but last attempt to synchronize the schema had failed. It is crucial that schema replication functions properly. See previous errors for more diagnostics. If this issue persists, please contact Microsoft Product Support Services for assistance. Error 8418: The replication operation failed because of a schema mismatch between the servers involved..
Also event ids 1203 are observed specifying the schema mismatch. I have verified the schema version is 87, which is the default version of AD on windows server 2016. The root DC shows the schema update successful event log as well.
Need help to resolve the issue.
Also what if i decided to demote this failed ADC installation, does it have any impact in my running environment.