Lottery for WooCommerce

Got this error: “The preview could not be loaded”.

Uncaught Error: Call to a member function get_lottery_ticket_count() on null in /public_html/wp-content/plugins/lottery-for-woocommerce/inc/frontend/class-lty-shortcodes.php:722.

When i delete: “return absint( $lottery_product->get_lottery_ticket_count() );” – it works, but only when deleted. However it then does not show the sold ticket count.

Please fix, i am unable to edit the page.