Array
(
    [type] => http://developer.mailchimp.com/documentation/mailchimp/guides/error-glossary/
    [title] => Invalid Resource
    [status] => 400
    [detail] => The resource submitted could not be validated. For field-specific details, see the 'errors' array.
    [instance] => 2bc1222d-27b2-48d7-9458-8df1f6fa9a77
    [errors] => Array
        (
            [0] => Array
                (
                    [field] => email_address
                    [message] => This value should not be blank.
                )

        )

)