The installation cannot continue because of the schema version mismatch between the target Active Directory forest and the ...

The installation cannot continue because of the schema version mismatch between the target Active Directory forest and the new domain controller. Please upgrade your Active Directory schema using "adprep /forestprep".
Forest schema version: %1!d!, required schema version: %2!d!. The Adprep utility is available on the Windows Server 2012 R2 installation media in the \support\adprep folder.