Entity Framework 6 - Knowledge Base (KB)

The name 'EntityState' does not exist in the current context

In ...Entity Framework..., this sometimes occurs when the ...System.data.entity... assembly is not added into the Project. But, why I didn't have this error before in other MVC project....it occurs sometimes but frequently and I have to add it manually in...

EF Code First The INSERT statement conflicted with the FOREIGN KEY constraint

When I try to insert a record in the database, I get this error message:...The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.Order_dbo.AspNetUsers_UserId". The conflict occurred in database "Test", table "dbo.AspNetUsers", column...