solaris roles cannot login directly

 oracle@solaris:~$ su - root
 Password:
 Oracle Corporation      SunOS 5.11      11.2    June
 root@solaris:~# cat /etc/user_attr
 #
 # Copyright (c) , , Oracle and/or its affiliates. All rights reserved.
 #
 # The system provided entries are stored in different files
 # under "/etc/user_attr.d".  They should not be copied to this file.
 #
 # Only local changes should be stored in this file.
 #
 root::::type=role
 oracle::::lock_after_retries=no;profiles=System Administrator;roles=root
 root@solaris:~# rolemod -K type=normal root
 root@solaris:~# cat /etc/user_attr
 #
 # Copyright (c) , , Oracle and/or its affiliates. All rights reserved.
 #
 # The system provided entries are stored in different files
 # under "/etc/user_attr.d".  They should not be copied to this file.
 #
 # Only local changes should be stored in this file.
 #
 oracle::::lock_after_retries=no;profiles=System Administrator;roles=root
 root@solaris:~#