ORA-24817: Unable to allocate the given chunk for current lob operation
Cause : The given size is increased to accomodate the number of bytes from server due to varying width db char/nchar set.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Use smaller chunk sizes when you have character set conversion between client/server or perform piece-wise read or write.
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.