PHP 7.2 Warning – Undefined Constant

Hi, I am getting the PHP warning message: “Use of undefined constant rating_tip_option – assumed ‘rating_tip_option’ (this will throw an Error in a future version of PHP)”

Location:
1. do_action(‘admin_notices’)
wp-admin/admin-header.php:276
2. mfcf7_zl_admin_rating_notice()
wp-includes/class-wp-hook.php:286
3. wp-content/plugins/multiline-files-for-contact-form-7/multiline-admin.php:179

Running PHP 7.2.16 / MySQL 5.6.43 / WordPress 5.1.1

Thanks!