Find and fix the error on the Wordpress site Woocommerce

Online store on Woocommerce, with improvements on the design page, there are 2 types of delivery: 1. With the cost and free, if you choose for free, then everything is OK, if you choose for a fee, then the Internal Server Error comes out.

The site hinkalbrothers.ru if you add the product to the cart, to the design and select Delivery: 200₽