Error on WC refund: id was called incorrectly

Hi,

I get the following error when doing a refund on WC3.4:

2018/05/29 13:43:37 [error] 21#21: *32482 FastCGI sent in stderr: “PHP message: id was called incorrectly. Order properties should not be accessed directly. Backtrace: do_action(‘wp_ajax_woocommerce_refund_line_items’), WP_Hook->do_action, WP_Hook->apply_filters, WC_AJAX::refund_line_items, wc_create_refund, do_action(‘woocommerce_order_fully_refunded’), WP_Hook->do_action, WP_Hook->apply_filters, WC_Emails::send_transactional_email, do_action_ref_array, WP_Hook->do_action, WP_Hook->apply_filters, WC_Email_Customer_Refunded_Order->trigger_full, WC_Email_Customer_Refunded_Order->trigger, WC_Email->get_content, WC_Email_Customer_Refunded_Order->get_content_html, wc_get_template_html, wc_get_template, include(‘/plugins/woocommerce/templates/emails/customer-refunded-order.php’), do_action(‘woocommerce_email_order_details’), WP_Hook->do_action, WP_Hook->apply_filters, WC_Emails->order_details, wc_get_template, include(‘/plugins/woocommerce/templates/emails/email-order-details.php’), wc_get_email_order_items, apply_filters(‘woocommerce_email_order_items_table’), WP_Hook->apply” while reading response header from upstream, client: 86.50.146.157, server: demo.site, request: “POST /wp-admin/admin-ajax.php?lang=en HTTP/1.1”, upstream: “fastcgi://127.0.0.1:20042”, host: “demo.site”, referrer: “https://demo.site/wp-admin/post.php?post=4353&action=edit”

Did the usual plugin disable analysis and the error disappears when I disable Enhanced Ecommerce Google Analytics Plugin. Seems there is some place in the refund branch a $product->id call?