Error 500

Hello,
We are having a problem on our website.
We cannot generate any pdf with the plugin since the last wordpress update.
Here is the PHP error :
Got error ‘PHP message: user_id 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, WC_AJAX::do_wc_ajax, do_action(‘wc_ajax_checkout’), WP_Hook->do_action, WP_Hook->apply_filters, WC_AJAX::checkout, WC_Checkout->process_checkout, do_action(‘woocommerce_checkout_order_processed’), WP_Hook->do_action, WP_Hook->apply_filters, remove_credits, WC_Abstract_Legacy_Order->__get, wc_doing_it_wrong. This message was added in version 3.0.PHP message: user_id 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, WC_AJAX::do_wc_ajax, do_action(‘wc_ajax_checkout’), WP_Hook->do_action, WP_Hook->apply_filters, WC_AJAX::checkout, WC_Checkout->process_checkout, WC_Checkout->process_order_payment, IGFW\\Models\\Gateways\\IGFW_Invoice_Gateway->process_payment, WC_Order->update_status, WC_Order->save, WC_Order->status_transition, do_action(‘woocommerce_order_status_pending_to_processing’), WP_Hook->do_action, WP_Hook->apply_filters, WC_Emails::send_transactional_email, do_action_ref_array(‘woocommerce_order_status_pending_to_processing_notification’), WP_Hook->do_action, WP_Hook->apply_filters, WC_Email_Customer_Processing_Order->trigger, WC_Email->get_content, WC_Email_Customer_Processing_Order->get_content_html, wc_get_template_html, wc_get_template, include…PHP message: PHP Fatal error: Uncaught Error: Class ‘rnwcinv\\pr\\fields\\PDFCustomField’ not found in /var/www/vhosts/sportserv.fr/sportserv.fr/wp-content/plugins/woo-pdf-invoice-builder/htmlgenerator/fields/FieldFactory.php:86\nStack trace:\n#0 /var/www/vhosts/sportserv.fr/sportserv.fr/wp-content/plugins/woo-pdf-invoice-builder/htmlgenerator/AreaGenerator.php(47): rnwcinv\\htmlgenerator\\fields\\FieldFactory::GetField(Object(stdClass), Object(rnwcinv\\htmlgenerator\\OrderValueRetriever))\n#1 /var/www/vhosts/sportserv.fr/sportserv.fr/wp-content/plugins/woo-pdf-invoice-builder/htmlgenerator/PageGenerator.php(61): rnwcinv\\htmlgenerator\\AreaGenerator->Generate()\n#2 /var/www/vhosts/sportserv.fr/sportserv.fr/wp-content/plugins/woo-pdf-invoice-builder/htmlgenerator/PageGenerator.php(36): rnwcinv\\htmlgenerator\\PageGenerator->GenerateArea(Object(stdClass), Array)\n#3 /var/www/vhosts/sportserv.fr/sportserv.fr/wp-content/plugins/woo-pdf-invoice-builder/htmlgenerator/DocumentGenerator.php(80): rnwcinv\\htmlgenerator\\Pa…’, referer: https://sportserv.fr/commande/?devis=1

Also, when I go to “Blank page/500 error resolver”, I have this error :
is_dir(): open_basedir restriction in effect. File(/.bzr) is not within the allowed path(s): (/var/www/vhosts/sportserv.fr/:/tmp/)

Please let me know what needs to be done.
Thanks and have a nice day !