ORA-22957: NULL is an invalid input to powermultiset and COLLECT functions
Cause : NULL was given as input to the powermultiset or COLLECT function.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Give a non-null value as input
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.