Fatal error

Hi there

Plugin was working fine but then all of sudden it is conflicting with woocommerce products. I cannot edit or delete or view products.
Error is like
Fatal error: Call to a member function get_cart() on null in /home/#######/public_html/wp-content/plugins/woocommerce-quick-donation/woocommerce-quick-donation.php on line 96

https://ww.wp.xz.cn/plugins/woocommerce-quick-donation/