opencart 1.5的问题

Question

网址my-site / admin

上有错误

  

致命错误：在非对象中调用成员函数isLogged（）   /home/mikolam/domains/mikola-m.com.ua/public_html/catalog/model/catalog/product.php   第65行

码

 public function getProducts($data = array()) {
        if ($this->customer->isLogged()) {
            $customer_group_id = $this->customer->getCustomerGroupId();
        } else {
            $customer_group_id = $this->config->get('config_customer_group_id');
        }   

        $sql = "SELECT p.product_id, (SELECT AVG(rating) AS total FROM " . DB_PREFIX . "review r1 WHERE r1.product_id = p.product_id AND r1.status = '1' GROUP BY r1.product_id) AS rating, (SELECT price FROM " . DB_PREFIX . "product_discount pd2 WHERE pd2.product_id = p.product_id AND pd2.customer_group_id = '" . (int)$customer_group_id . "' AND pd2.quantity = '1' AND ((pd2.date_start = '0000-00-00' OR pd2.date_start < NOW()) AND (pd2.date_end = '0000-00-00' OR pd2.date_end > NOW())) ORDER BY pd2.priority ASC, pd2.price ASC LIMIT 1) AS discount, (SELECT price FROM " . DB_PREFIX . "product_special ps WHERE ps.product_id = p.product_id AND ps.customer_group_id = '" . (int)$customer_group_id . "' AND ((ps.date_start = '0000-00-00' OR ps.date_start < NOW()) AND (ps.date_end = '0000-00-00' OR ps.date_end > NOW())) ORDER BY ps.priority ASC, ps.price ASC LIMIT 1) AS special"; 

        if (!empty($data['filter_category_id'])) {
            if (!empty($data['filter_sub_category'])) {
                $sql .= " FROM " . DB_PREFIX . "category_path cp LEFT JOIN " . DB_PREFIX . "product_to_category p2c ON (cp.category_id = p2c.category_id)";         
            } else {
                $sql .= " FROM " . DB_PREFIX . "product_to_category p2c";
            }