ORA-27475: "string.string" must be a string
Cause : An object of the wrong type was specified. For example, a table could have been passed to the drop_job() procedure.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Reissue a different command applicable to this object type or reissue the same command using an object of the valid type.
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.