Fatal error: Uncaught Error: Call to undefined function is_composite_product() in /home/celest28/public_html/wp-content/plugins/woo-add-gtin/includes/class-woo-gtin-functions.php:108 Stack trace: #0 /home/celest28/public_html/wp-includes/class-wp-hook.php(286): Woo_GTIN_Functions->scripts_styles('') #1 /home/celest28/public_html/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #2 /home/celest28/public_html/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #3 /home/celest28/public_html/wp-includes/script-loader.php(1447): do_action('wp_enqueue_scri...') #4 /home/celest28/public_html/wp-includes/class-wp-hook.php(286): wp_enqueue_scripts('') #5 /home/celest28/public_html/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #6 /home/celest28/public_html/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #7 /home/celest28/public_html/wp-includes/general-template.php(2614): do_action('wp_head') #8 /home/celest28/public_html/wp-content/themes/sydney/header.php(22): wp_head() #9 in /home/celest28/public_html/wp-content/plugins/woo-add-gtin/includes/class-woo-gtin-functions.php on line 108