When I create a coupon I get this error message. The coupon is created
Fatal error: Uncaught TypeError: Return value of YITH_Popup_Newsletter_Mailchimp::get_mailchimp_lists() must be an instance of mixed, bool returned in /home/customer/www/misslillianspaint.net/public_html/wp-content/plugins/yith-woocommerce-popup/includes/newsletter-integration/Mailchimp.php:287 Stack trace: #0 /home/customer/www/misslillianspaint.net/public_html/wp-content/plugins/yith-woocommerce-popup/includes/newsletter-integration/Mailchimp.php(145): YITH_Popup_Newsletter_Mailchimp->get_mailchimp_lists(false, 72844) #1 /home/customer/www/misslillianspaint.net/public_html/wp-includes/class-wp-hook.php(287): YITH_Popup_Newsletter_Mailchimp->add_metabox_field(Array) #2 /home/customer/www/misslillianspaint.net/public_html/wp-includes/plugin.php(212): WP_Hook->apply_filters(Array, Array) #3 /home/customer/www/misslillianspaint.net/public_html/wp-content/plugins/yith-woocommerce-popup/plugin-options/metabox/ypop_metabox.php(296): apply_filters('yith-popup-news...', Array) #4 /home/customer/www/misslillianspaint.net/public_h in /home/customer/www/misslillianspaint.net/public_html/wp-content/plugins/yith-woocommerce-popup/includes/newsletter-integration/Mailchimp.php on line 287