Adprep could not contact the Infrastructure FSMO. The Infrastucture FSMO must be reachable for this operation to proceed. ...

Adprep could not contact the Infrastructure FSMO. The Infrastucture FSMO must be reachable for this operation to proceed. 
[Status/Consequence]
The Active Directory GPO operations have not completed.
[User Action]
Check the log file ADPrep.log in the %1 directory for possible cause of failure.