Fatal error: Uncaught Error: Class "WC_Pre_Orders_Cart" not found in /customers/9/6/2/hydrema-shop.com/httpd.www/wp-content/plugins/woocommerce-pre-orders/includes/class-wc-pre-orders.php:191
Stack trace:
#0 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-content/plugins/woocommerce-pre-orders/includes/class-wc-pre-orders.php(88): WC_Pre_Orders->load_classes()
#1 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-content/plugins/woocommerce-pre-orders/woocommerce-pre-orders.php(81): WC_Pre_Orders->__construct('/customers/9/6/...')
#2 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-includes/class-wp-hook.php(324): woocommerce_pre_orders_init('')
#3 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#4 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#5 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-settings.php(559): do_action('plugins_loaded')
#6 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-config.php(96): require_once('/customers/9/6/...')
#7 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-load.php(50): require_once('/customers/9/6/...')
#8 /customers/9/6/2/hydrema-shop.com/httpd.www/wp-blog-header.php(13): require_once('/customers/9/6/...')
#9 /customers/9/6/2/hydrema-shop.com/httpd.www/index.php(17): require('/customers/9/6/...')
#10 {main}
  thrown in /customers/9/6/2/hydrema-shop.com/httpd.www/wp-content/plugins/woocommerce-pre-orders/includes/class-wc-pre-orders.php on line 191