ORA-16572: Data Guard configuration file not found
Cause : The Data Guard broker configuration file was either unavailable or did not exist.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Verify that the configuration file was successfully created. If the dg_broker_config_file[1|2] parameter was changed, ensure the filename on disk and the parameter value match, there is space on the device, and you have the right permissions.
Well, the reason for above error is that i have taken the above script from a 11g database and running it on 10g database. 11g has bring some changes in password management. Below code is executed on 11g and user created successfully, which is expected result.