包含不在实体框架中工作的声明

Question

这是我的代码..

_DbSet.Include(x => x.Dine_In_Orders)
                    .Include(x => x.Order_Details)
                    .Include(x => x.Dine_In_Orders)
                    .Include(x => x.Order_Details.Select(y => y.Product))
                    .Include(x => x.Order_Details.Select(y => y.Product.Kitchen_Products))
                    .Include(x => x.Order_Details.Select(y => y.Product.Kitchen_Products.Side_Order))
                    .Include(x => x.Order_Details.Select(z => z.Product
                        .Kitchen_Products.Side_Order.Where(n => n.Id == z.SO_Id)));

它抛出异常

"The Include path expression must refer to a navigation property defined on the type. Use dotted paths for reference navigation properties and the Select operator for collection navigation properties.Parameter name: path"

我尝试了所有我知道的但没有成功..如果我删除最后一个包含路径它完美工作但不给我想要的结果。请提出一些建议，