Flashback ON fails with ORA-38706 and ORA-38714

Problem Description:
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Whenever you tried to enable your database flashback feature it failed with errors.

SQL> alter database flashback on;
alter database flashback on
*
ERROR at line 1:
ORA-38706: Cannot turn on FLASHBACK DATABASE logging.
ORA-38714: Instance recovery required.

Cause of the problem:
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The database is abnormally terminated. In Order to Enable the Flashback option the database need to be cleaned shutdown. Enabling flashback database after crash or shutdown abort will lead to this error.

Solution of The Problem:
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1.Cleanly Shutdown of your database.

SHUTDOWN
or SHUTDOWN IMMEDIATE
or, SHUTDOWN TRANSACTIONAL

2.Mount the database.

SQL>ALTER DATABASE MOUNT;

3.Enable flashback.
SQL>Alter database flashback on;

4.Open the database.
SQL>ALTER DATABASE OPEN;