Adprep was unable to check the current user's group membership. Status/Consequence Adprep has stopped without making changes. ...

Adprep was unable to check the current user's group membership.
[Status/Consequence] 
Adprep has stopped without making changes.
[User Action] 
Verify the current logged on user is a member of Domain Admins group, Enterprise Admins group and Schema Admins group if /forestprep is specified, or is a member of Domain Admins group if /domainprep is specified.