Secure Admin must be enabled to access the DAS remotely.

Error:
     Secure Admin must be enabled to access the DAS remotely.

Description:
     The administration is not enabled to be used remotely, therefore requires to be enabled.
  
Solution:
       ./asadmin --host [host] --port [port] enable-secure-admin


Reference:
http://docs.oracle.com/cd/E18930_01/html/821-2435/gkomz.html