Gitblit with Active Directory

[ERROR] Error Connecting to LDAP
LDAPException(resultCode=49 (invalid credentials), errorMessage='80090308: LdapErr: DSID-0C0903A9, comment: AcceptSecurityContext error, data 52e, v1db1 ', diagnosticMessage='80090308: LdapErr: DSID-0C0903A9, comment: AcceptSecurityContext error, data 52e, v1db1 ')

This could be the wrong password.
So I tested with my personal Active Directory account and it worked.

realm.authenticationProviders = ldap
realm.ldap.server = ldap://192.168.0.2
realm.ldap.username = [DOMAINNAME]\\duncansungwkim
realm.ldap.password = [YourPassword]
realm.ldap.accountBase = CN=Users,DC=[domainname],DC=[your-org],DC=com

Any Active Directory account in the "Domain Users" group will work.
In fact, you should ask your Active Directory administrator for the password of a special account that is only for anthentication. That account should be only in the "Domain Users" group, which I believe has the least rights.