Cause: The user has entered wrong password consequently for maximum number of times specified by the user"s profile parameter FAILED_LOGIN_ATTEMPTS, or the DBA has locked the account

Action: Wait for passWORD_LOCK_TIME or contact DBA

When you get this ora error and, if you want to unlock account called SCOTT follow these steps.

From your command prompt, type
sqlplus "/ as sysdba"

Once logged in as SYSDBA, you need to unlock the SCOTT account

SQL> alter user scott account unlock;