Oracle Solution for Error ora-16659

ORA-16659: failover operation in progress

What triggered the Error:

A primary database that restarted contacted a standby database that is being failed over to.

What should we do to fix it:

Shut down the primary database and wait for failover to complete on the standby database. Once failover is complete, restart the old primary database. If the failover occurred due to fast-start failover, restarting the primary database after failover is complete allows it to be automatically reinstated as a standby database to the new primary database.