You're welcome, I am happy that it works for you...
I tried it with ldapadmin (which has a nicer ui imo but only for windows) now and could connect, here are my connection settings:
I also tried it on Nethserver command line and it works but I just managed to link a file, programs like ldapadmin import the jpg to ldap in base64, see https://www.openldap.org/lists/openldap-software/200612/msg00156.html
Created file test.ldif:
Imported the ldif to ldap:
ldapmodify -Z -h localhost -D uid=admin,ou=People,dc=directory,dc=nh -w 'SECRET' -f test.ldif