Empty HubSpot Response

CF7 Version: 4.6.1
WP Version: 4.7.1

Your Plugin Version: 1.0

I just made a test configuration and submission, and unfortunately, I got a failure (or well, lack of anything) in response.

Configuration: https://puu.sh/tVwCT/37a87843fd.png

Response (according to your “last debug log” feature on the settings page):

Array
(
    [STATUS_CODE] => 0
    [HUBSPOT_RESPONSE] => 
)

Any ideas on what’s going on, and how to resolve?

Thanks,
-Chris.