ORA-13769: Snapshots string and string do not exist.
Cause : The user attempted to select data from the workload repository using snapshots that do not exist.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Check the snapshot identifiers and retry the operation.
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.