ORA-16258: marking index unusable due to a constraint violation
Cause : A constraint violation occurred during the apply of a direct path load. The index will be marked unusable and the apply will be restarted.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
No action necessary. See alert log for index schema and name.
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.