[Membership 2 Pro] MailChimp Addon Errors

The MailChimp Addon settings page is blank. I also see the following errors in the error log:

PHP Fatal error: Using $this when not in object context in /home/cagle/public_html/wp-content/plugins/membership/app/addon/mailchimp/class-ms-addon-mailchimp.php on line 439

PHP Fatal error: Cannot use object of type stdClass as array in /home/cagle/public_html/wp-content/plugins/membership/app/addon/mailchimp/class-ms-addon-mailchimp.php on line 405