Oracle Solution for Error ora-16773

ORA-16773: cannot start Redo Apply

What triggered the Error:

The Data Guard broker failed to start Redo Apply.

What should we do to fix it:

Check the Data Guard broker log and Oracle alert log for more details. If the database is already open, the broker will not be able to start Redo Apply if the COMPATIBLE initialization parameter is set to a value less than 11.0.