EntityFramework6 ServerVersion return invalid operation - entity-framework-4

Question

i use code first to build web application.
i have two main entity "Product and Category".a class for DbContext and class for DatabaseIntializer as below.
namespace WingtipToys.Models
{
public class Product
{
[ScaffoldColumn(false)]
public int ProductID { get; set; }
[Required, StringLength(100), Display(Name = "Name")]
public string ProductName { get; set; }
[Required, StringLength(10000), Display(Name = "Product Description"), DataType(DataType.MultilineText)]
public string Description { get; set; }
public string ImagePath { get; set; }
[Display(Name = "Price")]
public double? UnitPrice { get; set; }
public int? CategoryID { get; set; }
public virtual Category Category { get; set; }
}
}
==================================================
namespace WingtipToys.Models
{
public class Category
{
[ScaffoldColumn(false)]
public int CategoryID { get; set; }
[Required, StringLength(100), Display(Name = "Name")]
public string CategoryName { get; set; }
[Display(Name = "Product Description")]
public string Description { get; set; }
public virtual ICollection<Product> Products { get; set; }
}
}
===========================================================
namespace WingtipToys.Models
{
public class ProductContext:DbContext
{
public ProductContext()
: base("WingtipToys")
{
}
public DbSet<Category> Categories { get; set; }
public DbSet<Product> Products { get; set; }
}
}
=========================================================
namespace WingtipToys.Models
{
public class
ProductDatabaseInitializer:DropCreateDatabaseIfModelChanges<ProductContext>
{
protected override void Seed(ProductContext context)
{
GetCategories().ForEach(c => context.Categories.Add(c));
GetProducts().ForEach(p=>context.Products.Add(p));
}
private static List<Category> GetCategories()
{
var categories = new List<Category> {
new Category
{
CategoryID = 1,
CategoryName = "Cars"
},
new Category
{
CategoryID = 2,
CategoryName = "Planes"
},
new Category
{
CategoryID = 3,
CategoryName = "Trucks"
},
new Category
{
CategoryID = 4,
CategoryName = "Boats"
},
new Category
{
CategoryID = 5,
CategoryName = "Rockets"
},
};
return categories;
}
private static List<Product> GetProducts()
{
var products = new List<Product> {
new Product
{
ProductID = 1,
ProductName = "Convertible Car",
Description = "This convertible car is fast! The engine is powered by a neutrino based battery (not included)." +
"Power it up and let it go!",
ImagePath="carconvert.png",
UnitPrice = 22.50,
CategoryID = 1
},
new Product
{
ProductID = 2,
ProductName = "Old-time Car",
Description = "There's nothing old about this toy car, except it's looks. Compatible with other old toy cars.",
ImagePath="carearly.png",
UnitPrice = 15.95,
CategoryID = 1
},
new Product
{
ProductID = 3,
ProductName = "Fast Car",
Description = "Yes this car is fast, but it also floats in water.",
ImagePath="carfast.png",
UnitPrice = 32.99,
CategoryID = 1
},
new Product
{
ProductID = 4,
ProductName = "Super Fast Car",
Description = "Use this super fast car to entertain guests. Lights and doors work!",
ImagePath="carfaster.png",
UnitPrice = 8.95,
CategoryID = 1
},
new Product
{
ProductID = 5,
ProductName = "Old Style Racer",
Description = "This old style racer can fly (with user assistance). Gravity controls flight duration." +
"No batteries required.",
ImagePath="carracer.png",
UnitPrice = 34.95,
CategoryID = 1
},
new Product
{
ProductID = 6,
ProductName = "Ace Plane",
Description = "Authentic airplane toy. Features realistic color and details.",
ImagePath="planeace.png",
UnitPrice = 95.00,
CategoryID = 2
},
new Product
{
ProductID = 7,
ProductName = "Glider",
Description = "This fun glider is made from real balsa wood. Some assembly required.",
ImagePath="planeglider.png",
UnitPrice = 4.95,
CategoryID = 2
},
new Product
{
ProductID = 8,
ProductName = "Paper Plane",
Description = "This paper plane is like no other paper plane. Some folding required.",
ImagePath="planepaper.png",
UnitPrice = 2.95,
CategoryID = 2
},
new Product
{
ProductID = 9,
ProductName = "Propeller Plane",
Description = "Rubber band powered plane features two wheels.",
ImagePath="planeprop.png",
UnitPrice = 32.95,
CategoryID = 2
},
new Product
{
ProductID = 10,
ProductName = "Early Truck",
Description = "This toy truck has a real gas powered engine. Requires regular tune ups.",
ImagePath="truckearly.png",
UnitPrice = 15.00,
CategoryID = 3
},
new Product
{
ProductID = 11,
ProductName = "Fire Truck",
Description = "You will have endless fun with this one quarter sized fire truck.",
ImagePath="truckfire.png",
UnitPrice = 26.00,
CategoryID = 3
},
new Product
{
ProductID = 12,
ProductName = "Big Truck",
Description = "This fun toy truck can be used to tow other trucks that are not as big.",
ImagePath="truckbig.png",
UnitPrice = 29.00,
CategoryID = 3
},
new Product
{
ProductID = 13,
ProductName = "Big Ship",
Description = "Is it a boat or a ship. Let this floating vehicle decide by using its " +
"artifically intelligent computer brain!",
ImagePath="boatbig.png",
UnitPrice = 95.00,
CategoryID = 4
},
new Product
{
ProductID = 14,
ProductName = "Paper Boat",
Description = "Floating fun for all! This toy boat can be assembled in seconds. Floats for minutes!" +
"Some folding required.",
ImagePath="boatpaper.png",
UnitPrice = 4.95,
CategoryID = 4
},
new Product
{
ProductID = 15,
ProductName = "Sail Boat",
Description = "Put this fun toy sail boat in the water and let it go!",
ImagePath="boatsail.png",
UnitPrice = 42.95,
CategoryID = 4
},
new Product
{
ProductID = 16,
ProductName = "Rocket",
Description = "This fun rocket will travel up to a height of 200 feet.",
ImagePath="rocket.png",
UnitPrice = 122.95,
CategoryID = 5
}
};
return products;
}
}
}
here my connection string
<add name="WingtipToys"
connectionString="Data Source=hanaa-pc\hanaa;Initial Catalog=wingtiptoys;Integrated Security=True"
providerName="System.Data.SqlClient"/>
and i call databaseintializer in global.asax
namespace WingtipToys
{
public class Global : HttpApplication
{
void Application_Start(object sender, EventArgs e)
{
// Code that runs on application startup
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
Database.SetInitializer(new ProductDatabaseInitializer());
}
}
}
in master file i use listview to get all categories from db:
public IQueryable<Category> GetCategories()
{
var _db = new ProductContext();
IQueryable<Category> query = _db.Categories;
return query;
}
when i run project with debugging at context class i got this from watch window:
i want to know why this always happen and how to fix it.
Thanks.