Oracle Solution for Error ora-16661

ORA-16661: the standby database needs to be reinstated

What triggered the Error:

A switchover or failover operation has caused this database to require reinstatement.

What should we do to fix it:

Use the DGMGRL REINSTATE DATABASE command or Enterprise Manager to reinstate the database. If the target database has flashback enabled and it has sufficient flashback logs, the database will be reinstated as a standby database for the current primary database.