I am facing the same issue after the last plugin update:
Error Code : Fatal error: Uncaught Error: Class “WC_Subscriptions_Cart” not found in …../wp-content/plugins/revolut-gateway-for-woocommerce/includes/gateways/class-wc-gateway-revolut-cc.php:589
I was already in contact with support. That didn’t help. Please fix the plugin!