Dataguard synchronization

 Hi All,

one of the archive logs in the standby shows it is not applied ,but the newly generated archive logs are applied in the standby,is this any problem?do we proper synch between primary and standby,when i try to register this arch i get this error as below,

It looks like there is proper synch for all the newly generated files but im only worried about this "56589"

STANDBY:

SQL>  SELECT max(sequence#) AS "STANDBY", applied FROM v$archived_log GROUP BY applied;

   STANDBY APPLIED

---------- ---------

     56589 NO

     56825 YES

 SQL> alter database register logfile '/u01/app/oracle/admin/***/arch/***_arch_R689250082_T1_S56589.arc';