ORA-16191: Primary log shipping client not logged on standby

The error appears in the ALRET log file AS :- 
Check that the primary and standby are using a password file
and remote_login_passwordfile is set to SHARED or EXCLUSIVE,
and that the SYS password is same in the password files. returning error ORA-16191
ORA-16191 -Primary log shipping client not logged on standby 

Solution :- 
1.Defer the remote archival destination (log_archive_dest_state_n) parameter in primary. In case of RAC defer LOG_ARCHIVE_DEST_STATE_n in all nodes.
2.check parameter REMOTE_PASSWORDFILE is set to either EXCLUSIVE or SHARED on the both database .
3.Delete the old password file and create the new one for both the DBs.In case of RAC shutdown all instance of standby before recreating the password file by below command :-

orapwd file=$ORACLE_HOME/dbs/orapw$ORACLE_SID password=sys entries=5 force=y ignorecase=Y 

4. set the parameter SEC_CASE_SENSITIVE_LOGON=FALSE on both DBs.
5.Enable the remote archival destination (log_archive_dest_state_n) parameter in primary.
6. Log into standby database and stop the recovery as

SQL> alter database recover managed standby database cancel;

7.  Now restart the recovery as

SQL>alter database recover managed standby database disconnect from session ;

8.Perform a log switch on the primary database and check the archive sequence ,archive destination  and alert logfile. 

SQL>select DEST_ID, STATUS, DESTINATION, ERROR from V$ARCHIVE_DEST;