Oracle Message ORA-10459 - cannot start media recovery on standby database; another instance may be open

ERRORcannot start media recovery on standby database; another instance may be open
CAUSEAn attempt was made to perform media recovery on a standby database while another instance performed recovery on the standby or had the standby open.
ACTIONClose the standby on all other instances, cancel any conflicting recovery session, and perform manual recovery.