Oracle Error ORA-28015: Account unlock attempted on read-only database but a conflicting account lockout on the primary exists

Oracle Error Message

ORA-28015: Account unlock attempted on read-only database but a conflicting account lockout on the primary exists

Reason for the Error

An attempt to unlock an account on a read-only database was prevented, because the account was previously marked as locked on the primary database. All attempts to unlock the account on the read-only database will be prevented as long as the overriding “account locked” condition exists at the primary database.

Solution

If this database is part of a Data Guard configuration, perform the account unlock action on the primary database. If this database is read-only, then set the database to read/write and perform the account unlock action.