The error message is typically due to a certificate issue. Please verify the certificate details. We have seen this issue with missing certificates, as well as with configuration issues related to the certificate. For example, using an IP address that does not match the fully qualified domain name the certificate was assigned to.
Please, refer to the CA Identity Management & Governance Connectors Guides for the Microsoft Active Directory, Microsoft Exchange, and Microsoft Lync connectors, :How to Connect to Active Directory for very detailed instructions on implementing the connector both in a secure, and non-secure environments: