ORA-06436: ssaio: asynchronous I/O failed due to incorrect parameters.
Cause : The Asynchronous I/O system call returned an error.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
The additional information indicates the block number. Look up the additional information returned in your operating system manual.
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.