The versions affected are :  Microsoft Exchange Server 2013, Microsoft Exchange Server 2016 , Microsoft Exchange Server 2019  

using System.Collections.Generic; 


namespace EF_Sample07.DomainClasses
{
    public class Category
    {
        public int Id { get; set; }
        public virtual string Name { get; set; }
        public virtual string Title { get; set; } 

        public virtual ICollection<Product> Products { get; set; }
    }
} 

using System.ComponentModel.DataAnnotations; 


namespace EF_Sample07.DomainClasses
{
    public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public decimal Price { get; set; }         


        [ForeignKey("CategoryId")]
        public virtual Category Category { get; set; }
        public int CategoryId { get; set; }
    }
} 

using System.Data.Entity;
using System; 


namespace EF_Sample07.DataLayer.Context
{
    public interface IUnitOfWork
    {
        IDbSet<TEntity> Set<TEntity>() where TEntity : class;
        int SaveChanges();
    }
} 

using System.Data.Entity;
using EF_Sample07.DomainClasses; 


namespace EF_Sample07.DataLayer.Context
{
    public class Sample07Context : DbContext, IUnitOfWork
    {
        public DbSet<Category> Categories { set; get; }
        public DbSet<Product> Products { set; get; } 


        #region IUnitOfWork Members
        public new IDbSet<TEntity> Set<TEntity>() where TEntity : class
        {
            return base.Set<TEntity>();
        }
        #endregion
    }
} 

uow.Set<Product> 

using EF_Sample07.DomainClasses;
using System.Collections.Generic; 


namespace EF_Sample07.ServiceLayer
{
    public interface ICategoryService
    {
        void AddNewCategory(Category category);
        IList<Category> GetAllCategories();
    }
} 

using EF_Sample07.DomainClasses;
using System.Collections.Generic; 


namespace EF_Sample07.ServiceLayer
{
    public interface IProductService
    {
        void AddNewProduct(Product product);
        IList<Product> GetAllProducts();
    }
} 

using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using EF_Sample07.DataLayer.Context;
using EF_Sample07.DomainClasses; 


namespace EF_Sample07.ServiceLayer
{
    public class EfCategoryService : ICategoryService
    {
        IUnitOfWork _uow;
        IDbSet<Category> _categories;
        public EfCategoryService(IUnitOfWork uow)
        {
            _uow = uow;
            _categories = _uow.Set<Category>();
        } 


        public void AddNewCategory(Category category)
        {
            _categories.Add(category);
        } 


        public IList<Category> GetAllCategories()
        {
            return _categories.ToList();
        }
    }
} 

using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using EF_Sample07.DataLayer.Context;
using EF_Sample07.DomainClasses; 


namespace EF_Sample07.ServiceLayer
{
    public class EfProductService : IProductService
    {
        IUnitOfWork _uow;
        IDbSet<Product> _products;
        public EfProductService(IUnitOfWork uow)
        {
            _uow = uow;
            _products = _uow.Set<Product>();
        } 


        public void AddNewProduct(Product product)
        {
            _products.Add(product);
        } 


        public IList<Product> GetAllProducts()
        {
            return _products.Include(x => x.Category).ToList();
        }
    }
} 

using System.Collections.Generic;
using System.Data.Entity;
using EF_Sample07.DataLayer.Context;
using EF_Sample07.DomainClasses;
using EF_Sample07.ServiceLayer;
using StructureMap; 


namespace EF_Sample07
{
    class Program
    {
        static void Main(string[] args)
        {
            Database.SetInitializer(new MigrateDatabaseToLatestVersion<Sample07Context, Configuration>());


            HibernatingRhinos.Profiler.Appender.EntityFramework.EntityFrameworkProfiler.Initialize();
            ObjectFactory.Initialize(x =>
            {
                x.For<IUnitOfWork>().CacheBy(InstanceScope.Hybrid).Use<Sample07Context>();
                x.For<ICategoryService>().Use<EfCategoryService>();
            }); 


            var uow = ObjectFactory.GetInstance<IUnitOfWork>();
            var categoryService = ObjectFactory.GetInstance<ICategoryService>(); 


            var product1 = new Product { Name = "P100", Price = 100 };
            var product2 = new Product { Name = "P200", Price = 200 };
            var category1 = new Category
            {
                Name = "Cat100",
                Title = "Title100",
                Products = new List<Product> { product1, product2 }
            };
            categoryService.AddNewCategory(category1);
            uow.SaveChanges();            
        }
    }
} 

public enum InstanceScope
{
        PerRequest = 0,
        Singleton = 1,
        ThreadLocal = 2,
        HttpContext = 3,
        Hybrid = 4,
        HttpSession = 5,
        HybridHttpSession = 6,
        Unique = 7,
        Transient = 8,
} 

using System.Web.Mvc;
using EF_Sample07.DomainClasses;
using EF_Sample07.ServiceLayer;
using EF_Sample07.DataLayer.Context;
using System.Collections.Generic; 


namespace EF_Sample07.MvcAppSample.Controllers
{
    public class HomeController : Controller
    {
        IProductService _productService;
        ICategoryService _categoryService;
        IUnitOfWork _uow;
        public HomeController(IUnitOfWork uow, IProductService productService, ICategoryService categoryService)
        {
            _productService = productService;
            _categoryService = categoryService;
            _uow = uow;
        } 


        [HttpGet]
        public ActionResult Index()
        {
            var list = _productService.GetAllProducts();
            return View(list);
        }


        [HttpGet]
        public ActionResult Create()
        {
            ViewBag.CategoriesList = new SelectList(_categoryService.GetAllCategories(), "Id", "Name");
            return View();
        } 


        [HttpPost]
        public ActionResult Create(Product product)
        {
            if (this.ModelState.IsValid)
            {
                _productService.AddNewProduct(product);
                _uow.SaveChanges();
            }


            return RedirectToAction("Index");
        } 


        [HttpGet]
        public ActionResult CreateCategory()
        {
            return View();
        } 


        [HttpPost]
        public ActionResult CreateCategory(Category category)
        {
            if (this.ModelState.IsValid)
            {
                _categoryService.AddNewCategory(category);
                _uow.SaveChanges();
            }

            return RedirectToAction("Index");
        }
    }
} 

using System;
using System.Data.Entity;
using System.Web.Mvc;
using System.Web.Routing;
using EF_Sample07.DataLayer.Context;
using EF_Sample07.ServiceLayer;
using StructureMap; 


namespace EF_Sample07.MvcAppSample

{
    // Note: For instructions on enabling IIS6 or IIS7 classic mode, 
    // visit http://go.microsoft.com/?LinkId=9394801 


    public class MvcApplication : System.Web.HttpApplication
    {
        public static void RegisterGlobalFilters(GlobalFilterCollection filters)
        {
            filters.Add(new HandleErrorAttribute());
        } 


        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); 

            routes.MapRoute(
                "Default", // Route name
                "{controller}/{action}/{id}", // URL with parameters
                new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
            );
        } 


        protected void Application_Start()
        {
            Database.SetInitializer(new MigrateDatabaseToLatestVersion<Sample07Context, Configuration>());
            HibernatingRhinos.Profiler.Appender.EntityFramework.EntityFrameworkProfiler.Initialize();
            AreaRegistration.RegisterAllAreas();
            RegisterGlobalFilters(GlobalFilters.Filters);
            RegisterRoutes(RouteTable.Routes);
            initStructureMap();
        } 


        private static void initStructureMap()
        {
            ObjectFactory.Initialize(x =>
            {
                x.For<IUnitOfWork>().HttpContextScoped().Use(() => new Sample07Context());
                x.ForRequestedType<ICategoryService>().TheDefaultIsConcreteType<EfCategoryService>();
                x.ForRequestedType<IProductService>().TheDefaultIsConcreteType<EfProductService>();
            });


            //Set current Controller factory as StructureMapControllerFactory
            ControllerBuilder.Current.SetControllerFactory(new StructureMapControllerFactory());
        } 


        protected void Application_EndRequest(object sender, EventArgs e)
        {
            ObjectFactory.ReleaseAndDisposeAllHttpScopedObjects();
        }
    } 


    public class StructureMapControllerFactory : DefaultControllerFactory
    {
        protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
        {
            return ObjectFactory.GetInstance(controllerType) as Controller;
        }
    }
} 

using System;
using System.Data.Entity;
using EF_Sample07.DataLayer.Context;
using EF_Sample07.ServiceLayer;
using StructureMap; 


namespace EF_Sample07.WebFormsAppSample
{
    public class Global : System.Web.HttpApplication
    {
        private static void initStructureMap()
        {
            ObjectFactory.Initialize(x =>
            {
                x.For<IUnitOfWork>().HttpContextScoped().Use(() => new Sample07Context());
                x.ForRequestedType<ICategoryService>().TheDefaultIsConcreteType<EfCategoryService>();
                x.ForRequestedType<IProductService>().TheDefaultIsConcreteType<EfProductService>(); 

                x.SetAllProperties(y=>
                {
                    y.OfType<IUnitOfWork>();
                    y.OfType<ICategoryService>();
                    y.OfType<IProductService>();
                });
            });
        } 


        void Application_Start(object sender, EventArgs e)
        {
            Database.SetInitializer(new MigrateDatabaseToLatestVersion<Sample07Context, Configuration>());
            HibernatingRhinos.Profiler.Appender.EntityFramework.EntityFrameworkProfiler.Initialize();
            initStructureMap();
        } 


        void Application_EndRequest(object sender, EventArgs e)
        {
            ObjectFactory.ReleaseAndDisposeAllHttpScopedObjects();
        } 

using System.Web.UI;
using StructureMap; 


namespace EF_Sample07.WebFormsAppSample
{
    public class BasePage : Page
    {
        public BasePage()
        {
            ObjectFactory.BuildUp(this);
        }
    }
} 

using System;
using EF_Sample07.DataLayer.Context;
using EF_Sample07.DomainClasses;
using EF_Sample07.ServiceLayer; 


namespace EF_Sample07.WebFormsAppSample
{
    public partial class AddProduct : BasePage
    {
        public IUnitOfWork UoW { set; get; }
        public IProductService ProductService { set; get; }
        public ICategoryService CategoryService { set; get; } 


        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                bindToCategories();
            }
        } 


        private void bindToCategories()
        {
            ddlCategories.DataTextField = "Name";
            ddlCategories.DataValueField = "Id";
            ddlCategories.DataSource = CategoryService.GetAllCategories();
            ddlCategories.DataBind();
        } 


        protected void btnAdd_Click(object sender, EventArgs e)
        {
            var product = new Product
            {
                Name = txtName.Text,
                Price = int.Parse(txtPrice.Text),
                CategoryId = int.Parse(ddlCategories.SelectedItem.Value)
            };
            ProductService.AddNewProduct(product);
            UoW.SaveChanges();
            Response.Redirect("~/Default.aspx");
        }
    }
}