Adprep could not contact the Infrastructure FSMO for domain %1. The Infrastructure FSMO must be reachable for this operation ...

Adprep could not contact the Infrastructure FSMO for domain %1. The Infrastructure FSMO must be reachable for this operation to proceed. 
[Status/Consequence]
The Active Directory Domain Services DNS partitions are not prepared for Read Only DCs.
[User Action] 
Check the log file ADPrep.log in the %2 directory for possible cause of failure.