Can´t connect my EX4100 to the Windows AD


I´m trying to connect my NAS EX4100 to the Active Directory of the company, but I have this message:

" Error al unirse al dominio.No se ha consultado la info del DC para el dominio ‘SECCR.CORP’ por RPC:Indicates a referenced user name and authentication information are valid, but some user account r."*

Any idea about what can I do, I need to connect to the AD because some users have the NAS like an external drive.