Oracle Solution for Error ora-16649

ORA-16649: possible failover to another database prevents this database being opened

What triggered the Error:

An attempt to open the database was made either when a failover occurred or while fast-start failover was enabled and the fast-start failover status could not be evaluated.

What should we do to fix it:

Check if a failover did occur. If fast-start failover is enabled, and a failover did not occur, ensure that connectivity exists between this database and either the observer or the target standby database. Then, try opening the database again.