Enabling WP debug because of an Error 500 (not related to this plugin), I noticed these 'PHP Notice'
[15-Sep-2016 15:11:33 UTC] PHP Notice: Undefined index: setup.filters in /var/www/website_path/wp-content/plugins/flagship-for-woocommerce/includes/components/hook/class.flagship-hook.php on line 38
[15-Sep-2016 15:11:33 UTC] PHP Notice: Undefined index: setup.actions in /var/www/website_path/wp-content/plugins/flagship-for-woocommerce/includes/components/hook/class.flagship-hook.php on line 38
[15-Sep-2016 15:11:33 UTC] PHP Notice: Undefined index: metabox.actions in /var/www/website_path/wp-content/plugins/flagship-for-woocommerce/includes/components/hook/class.flagship-hook.php on line 38
[15-Sep-2016 15:11:34 UTC] PHP Notice: Undefined index: settings.filters in /var/www/website_path/wp-content/plugins/flagship-for-woocommerce/includes/components/hook/class.flagship-hook.php on line 38