You are unable to login to the Advanced Threat Protection (ATP) web interface via Active Directory (AD) credentials following an upgrade to version 3.2. Active Directory authentication was working prior to the upgrade. You are still able to login with a local administrator account. Should you attempt to update the Active Directory settings within ATP, then you may run into a certificate error.
The SSL handshake is failing because the "Primary IP or Hostname" field does not match the Common Name (CN) or any of the Subject Alternative Name(s) on the LDAPS public certificate. This is required in version 3.2.