Server error.log

Hi,
attached my Server error.log:

2020/09/10 23:24:23 [error] 32754#32754: *135164 FastCGI sent in stderr: "opaypalplus.express_checkout_request/cart/createOrder'), WP_Hook->do_action, WP_Hook->apply_filters, WCPayPalPlus\ExpressCheckoutGateway\CartCheckout->createOrder, WCPayPalPlus\Payment\PaymentCreator->create, WCPayPalPlus\Payment\PaymentCreator->payment, WCPayPalPlus\Payment\PaymentCreator->details, WCPayPalPlus\Payment\CartData->subTotal, WCPayPalPlus\Payment\CartData->itemsList, WCPayPalPlus\Payment\CartData->item, WCPayPalPlus\Payment\CartItemData->get_sku, WC_Abstract_Legacy_Product->__get, wc_doing_it_wrong. This message was added in version 3.0.PHP message: parent was called incorrectly. Produkteigenschaften sollten nicht direkt abgerufen werden. Backtrace: do_action('wp_ajax_nopriv_paypal_express_checkout_request'), WP_Hook->do_action, WP_Hook->apply_filters, WCPayPalPlus\ExpressCheckoutGateway\AjaxHandler->handle, WCPayPalPlus\ExpressCheckoutGateway\Dispatcher->dispatch, do_action('woopaypalplus.express_checkout_request/cart/createOrder'), WP_Hook->do_action, WP_Hook->apply_filters, WCPayPalPlus\ExpressCheckoutGateway\CartCheckout->createOrder, WCPayPalPlus\Payment\PaymentCreator->create, WCPayPalPlus\Payment\PaymentCreator->payment, WCPayPalPlus\Payment\PaymentCreator->details, WCPayPalPlus\Payment\CartData->subTotal, WCPayPalPlus\Payment\CartData->itemsList, WCPayPalPlus\Payment\CartData->item, WCPayPalPlus\Payment\CartItemData->get_sku, WC_Abstract_Legacy_Product->__get, wc_doing_it_wrong. This message was added in version 3.0.PHP message: parent was called incorrectly. Produkteigenschaften sollten nicht direkt abgerufen werden. Backtrace: do_action('wp_ajax_nopriv_paypal_express_checkout_request'), WP_Hook->do_action, WP_Hook->apply_filters, WCPayPalPlus\ExpressCheckoutGateway\AjaxHandler->handle, WCPayPalPlus\ExpressCheckoutGateway\Dispatcher->dispatch, do_action('woopaypalplus.express_checkout_request/cart/createOrder'), WP_Hook->do_action, WP_Hook->apply_filters, WCPayPalPlus\ExpressCheckoutGateway\CartCheckout->createOrder,