Problem with LDAP Sub Domains

We configured the LDAP connector for our Active Directory domain. We also use multiple baseDNs and for our root domain it worked fine.
But we have also several subdomains at our forest. If we add the baseDNs for the subdomains, the users can not login.

At the ccnet.log we get the following error:
[08/09/17 12:57:47] user-mgr.c(472): ldap_search user ‘’ failed for base ou=users,dc=site,dc=example,dc=local : Operations error:
[08/09/17 12:57:47] user-mgr.c(473) : Please check BASE setting in ccnet.conf

The baseDN for the OU is correct. I checked it several times.

I also tried to use the Global Catalog with ldap://123.456.78.9:3268. But I got the same error.

Is there a possibility to add more than one domain controllers to add the subdomains?

Thanks in advance!

Has anyone any idea?

I would be also happy for the information, if it is not possible to connect Seafile with active director subdomain.

In this case I know that Seafile is not the right product for us.