Oracle Message ORA-16791 - unable to check the existence of the standby redo logs

ERRORunable to check the existence of the standby redo logs
CAUSEThe database may not be mounted, or the query of the V$STANDBY_LOG fixed view failed.
ACTIONEnsure the database is mounted and query the V$STANDBY_LOG fixed view to see if the problem has been corrected, and retry the operation.