nginx error logs after woo 3.0.3

my nginx logs keep throwing this error every 1 minute without doing anything!!

2017/04/19 20:10:01 [error] 1250#1250: *311 FastCGI sent in stderr: “PHP message: id was called incorrectly. Product properties should not be accessed directly. Backtrace: require_once(‘wp-load.php’), require_once(‘wp-config.php’), require_once(‘wp-settings.php’), do_action(‘wp_loaded’), WP_Hook->do_action, WP_Hook->apply_filters, WC_Cart->init, WC_Cart->get_cart_from_session, WC_Product->is_purchasable, apply_filters(‘woocommerce_is_purchasable’), WP_Hook->apply_filters, WC_Smart_Coupons->make_product_purchasable, WC_Abstract_Legacy_Product->__get, wc_doing_it_wrong. This message was added in version 3.0” while reading response header from upstream, client: 1x.xx2.1xx.1xx, server: xxxxx.net, request: “POST /wp-admin/admin-ajax.php HTTP/1.1”, upstream: “fastcgi://127.0.0.1:9001”, host: “xxxxxx.net”, referrer: “https://xxxxx.net/wp-admin/plugins.php”