Membership 2 Pro Mailchimp Integration addon Fatal error

Getting a fatal error when Mailchimp addon is active
PHP Fatal error: Uncaught Error: Cannot use object of type WP_Error as array in /srv/www/wordpress-default/public_html/wp-content/plugins/membership/lib/mailchimp-api/Mailchimp.php:61

The error causes Memberships details not being displayed http://take.ms/NQ11A