Once I have upgraded WooCommerce plugin to the latest version I started getting this error in the error_log file:
10-May-2017 12:19:25 UTC] billing_last_name was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_address_1 was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_address_2 was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_postcode was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_country was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_phone was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_first_name was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_last_name was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_phone was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_address_1 was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_state was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_city was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_postcode was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_postcode was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_country was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_email was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] order_total was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_first_name was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] billing_last_name was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] shipping_address_1 was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] shipping_address_2 was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] shipping_city was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] shipping_state was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] shipping_country was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.
[10-May-2017 12:19:25 UTC] shipping_postcode was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::do_wc_ajax, do_action('wc_ajax_checkout'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, WC_Gateway_payroll_creditcard_wc->process_payment, WC_Gateway_payroll_creditcard_wc->get_payroll_args, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.

How Can if fix the plugin, this is the code:

Read more here: WooCommerce Issue After Upgraded to The latest version


Solution:

If you know the solution of this issue, please leave us a reply in Comment section, to update the question.


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