Can't synchronize to active directory server

hello im from public institutions in my county im try use seafile comunity nad cant add user from my active directory server, im looking for a private hosted cloud server wich can colaboarate with my AD server

i use this code

[LDAP]
HOST = ldap://172.16.20.5/
BASE = cn=users,dc=domain,dc=com
USER_DN = admin@domain.com
PASSWORD = xxxxxxxxxxxx
LOGIN_ATTR = mail

in login page i try with user admin@domain.com but cant login

What log files saying?