A custom attribute is added in Domino. Directory Connector has been configured to add the custom attribute. A mapping from the Notes custom attribute is set to an AD attribute. However, Directory Connector does not bind against the custom attribute.
Verify the custom attribute is listed in the Domino LDAP schema by using Softerra LDAP Browser. If the attribute is not listed in the Attribute Types list on the SchemaViewer box, then that attribute is not in the LDAP schema. If assistance is required with altering the Domino LDAP schema, we would recommend contacting IBM directly.