ORA-15164: cluster rolling downgrade incomplete
Cause : The cluster was still performing rolling downgrade.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Ensure that all the instances in the cluster are downgraded before retrying the command.
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.