Получаю ошибку при использовании XML в Retrofit

public interface ServiceApi {
        @GET("*****")
        Observable<ModelSearchItems> getSearchItems();
    }

public class RequestApi {
    public static Retrofit init(){
        return new Retrofit.Builder()
                .baseUrl("*****")
                .addConverterFactory(SimpleXmlConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .build();
    }
    public static Observable<ModelSearchItems> getSearchItems(){
        Retrofit retrofit=init();
        ServiceApi serviceApi=retrofit.create(ServiceApi.class);           
        return serviceApi.getSearchItems(); //Тут ошибка
    }
}

@Root(name = "response")
public class ModelSearchItems {
    private String code;
    private List<ItemBean> message;
    public String getCode() {
        return code;
    }
    public void setCode(String code) {
        this.code = code;
    }
    public List<ItemBean> getMessage() {
        return message;
    }
    public void setMessage(List<ItemBean> message) {
        this.message = message;
    }
    @Root(name = "item")
    public static class ItemBean {
        private String point_id;
        private String shop_id;
        private String point_address;
        private String point_coords;
        private String point_rank;
        private String point_distance;
        private String point_time_id;
        private String shop_name;
        private String shop_logo;
        private String shop_rank;
        private String currency_id;
        private String item_is_liked;
        private String item_id;
        private String item_name;
        private String item_image;
        private String item_price;
        private String item_bonus_amount;
        private String item_bonus_price;
        private String item_likes;
        private String item_shares;
        private String item_comments;
        private String group_type;
        public String getPoint_id() {
            return point_id;
        }
        public void setPoint_id(String point_id) {
            this.point_id = point_id;
        }
        public String getShop_id() {
            return shop_id;
        }
        public void setShop_id(String shop_id) {
            this.shop_id = shop_id;
        }
        public String getPoint_address() {
            return point_address;
        }
        public void setPoint_address(String point_address) {
            this.point_address = point_address;
        }
        public String getPoint_coords() {
            return point_coords;
        }
        public void setPoint_coords(String point_coords) {
            this.point_coords = point_coords;
        }
        public String getPoint_rank() {
            return point_rank;
        }
        public void setPoint_rank(String point_rank) {
            this.point_rank = point_rank;
        }
        public String getPoint_distance() {
            return point_distance;
        }
        public void setPoint_distance(String point_distance) {
            this.point_distance = point_distance;
        }
        public String getPoint_time_id() {
            return point_time_id;
        }
        public void setPoint_time_id(String point_time_id) {
            this.point_time_id = point_time_id;
        }
        public String getShop_name() {
            return shop_name;
        }
        public void setShop_name(String shop_name) {
            this.shop_name = shop_name;
        }
        public String getShop_logo() {
            return shop_logo;
        }
        public void setShop_logo(String shop_logo) {
            this.shop_logo = shop_logo;
        }
        public String getShop_rank() {
            return shop_rank;
        }
        public void setShop_rank(String shop_rank) {
            this.shop_rank = shop_rank;
        }
        public String getCurrency_id() {
            return currency_id;
        }
        public void setCurrency_id(String currency_id) {
            this.currency_id = currency_id;
        }
        public String getItem_is_liked() {
            return item_is_liked;
        }
        public void setItem_is_liked(String item_is_liked) {
            this.item_is_liked = item_is_liked;
        }
        public String getItem_id() {
            return item_id;
        }
        public void setItem_id(String item_id) {
            this.item_id = item_id;
        }
        public String getItem_name() {
            return item_name;
        }
        public void setItem_name(String item_name) {
            this.item_name = item_name;
        }
        public String getItem_image() {
            return item_image;
        }
        public void setItem_image(String item_image) {
            this.item_image = item_image;
        }
        public String getItem_price() {
            return item_price;
        }
        public void setItem_price(String item_price) {
            this.item_price = item_price;
        }
        public String getItem_bonus_amount() {
            return item_bonus_amount;
        }
        public void setItem_bonus_amount(String item_bonus_amount) {
            this.item_bonus_amount = item_bonus_amount;
        }
        public String getItem_bonus_price() {
            return item_bonus_price;
        }
        public void setItem_bonus_price(String item_bonus_price) {
            this.item_bonus_price = item_bonus_price;
        }
        public String getItem_likes() {
            return item_likes;
        }
        public void setItem_likes(String item_likes) {
            this.item_likes = item_likes;
        }
        public String getItem_shares() {
            return item_shares;
        }
        public void setItem_shares(String item_shares) {
            this.item_shares = item_shares;
        }
        public String getItem_comments() {
            return item_comments;
        }
        public void setItem_comments(String item_comments) {
            this.item_comments = item_comments;
        }
        public String getGroup_type() {
            return group_type;
        }
        public void setGroup_type(String group_type) {
            this.group_type = group_type;
        }
    }
}