Problem with Active Directory-Connection

While I’m trying to set up the Active Directory-Connection I get this error:

check_domain: [u'Connection to AD Server my.ucs.intranet failed (CLDAP: 3221226038)'])

This is what the connector-status.log looks like:

Wed Nov 27 22:04:15 2019
connector/ad/ldap/host not set

Can someone help me?
If you need more information to help please just ask.

Btw. “slapd” is running.