Oracle Solution for Error ora-16574

ORA-16574: switchover disallowed when required databases are shut down

What triggered the Error:

Switchover failed because either the primary database or the designated standby database were shut down.

What should we do to fix it:

Ensure that the primary and standby databases are running and that primary database is shipping redo data to the designated standby database. Also ensure that that the designated standby database is applying the redo data received from the primary database.