سلام جناب مهندس.یک پروژه ای دارم وقتی میزنم که اجرا بشه خطای

The type or namespace name 'DbContext' could not be found (are you missing a using directive or an assembly reference?)

میاد وقتی EntityFramework.dll رو حذف می کنم دوباره نصب میکنم بازهم خطا میده اکثر ورژن EntityFramework.dll رو تست کردم مشکلش برطرف نمیشه اگه راهنمایی کنید ممنون میشم.کدی هم که مشکل داره در زیر قرار دادم

//------------------------------------------------------------------------------
// <auto-generated>
//    This code was generated from a template.
//
//    Manual changes to this file may cause unexpected behavior in your application.
//    Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

using System;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Data.Objects;
using System.Data.Objects.DataClasses;
using System.Linq;

public partial class MrchEntities : DbContext
{
    public MrchEntities()
        : base("name=MrchEntities")
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        throw new UnintentionalCodeFirstException();
    }

    public DbSet<Opration> Oprations { get; set; }
    public DbSet<OprationProcess> OprationProcesses { get; set; }
    public DbSet<OprationType> OprationTypes { get; set; }
    public DbSet<Request> Requests { get; set; }
    public DbSet<Role> Roles { get; set; }
    public DbSet<sysdiagram> sysdiagrams { get; set; }
    public DbSet<User> Users { get; set; }

    public virtual int sp_alterdiagram(string diagramname, Nullable<int> owner_id, Nullable<int> version, byte[] definition)
    {
        var diagramnameParameter = diagramname != null ?
            new ObjectParameter("diagramname", diagramname) :
            new ObjectParameter("diagramname", typeof(string));

        var owner_idParameter = owner_id.HasValue ?
            new ObjectParameter("owner_id", owner_id) :
            new ObjectParameter("owner_id", typeof(int));

        var versionParameter = version.HasValue ?
            new ObjectParameter("version", version) :
            new ObjectParameter("version", typeof(int));

        var definitionParameter = definition != null ?
            new ObjectParameter("definition", definition) :
            new ObjectParameter("definition", typeof(byte[]));

        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction("sp_alterdiagram", diagramnameParameter, owner_idParameter, versionParameter, definitionParameter);
    }

    public virtual int sp_creatediagram(string diagramname, Nullable<int> owner_id, Nullable<int> version, byte[] definition)
    {
        var diagramnameParameter = diagramname != null ?
            new ObjectParameter("diagramname", diagramname) :
            new ObjectParameter("diagramname", typeof(string));

        var owner_idParameter = owner_id.HasValue ?
            new ObjectParameter("owner_id", owner_id) :
            new ObjectParameter("owner_id", typeof(int));

        var versionParameter = version.HasValue ?
            new ObjectParameter("version", version) :
            new ObjectParameter("version", typeof(int));

        var definitionParameter = definition != null ?
            new ObjectParameter("definition", definition) :
            new ObjectParameter("definition", typeof(byte[]));

        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction("sp_creatediagram", diagramnameParameter, owner_idParameter, versionParameter, definitionParameter);
    }

    public virtual int sp_dropdiagram(string diagramname, Nullable<int> owner_id)
    {
        var diagramnameParameter = diagramname != null ?
            new ObjectParameter("diagramname", diagramname) :
            new ObjectParameter("diagramname", typeof(string));

        var owner_idParameter = owner_id.HasValue ?
            new ObjectParameter("owner_id", owner_id) :
            new ObjectParameter("owner_id", typeof(int));

        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction("sp_dropdiagram", diagramnameParameter, owner_idParameter);
    }

    public virtual ObjectResult<sp_helpdiagramdefinition_Result> sp_helpdiagramdefinition(string diagramname, Nullable<int> owner_id)
    {
        var diagramnameParameter = diagramname != null ?
            new ObjectParameter("diagramname", diagramname) :
            new ObjectParameter("diagramname", typeof(string));

        var owner_idParameter = owner_id.HasValue ?
            new ObjectParameter("owner_id", owner_id) :
            new ObjectParameter("owner_id", typeof(int));

        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction<sp_helpdiagramdefinition_Result>("sp_helpdiagramdefinition", diagramnameParameter, owner_idParameter);
    }

    public virtual ObjectResult<sp_helpdiagrams_Result> sp_helpdiagrams(string diagramname, Nullable<int> owner_id)
    {
        var diagramnameParameter = diagramname != null ?
            new ObjectParameter("diagramname", diagramname) :
            new ObjectParameter("diagramname", typeof(string));

        var owner_idParameter = owner_id.HasValue ?
            new ObjectParameter("owner_id", owner_id) :
            new ObjectParameter("owner_id", typeof(int));

        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction<sp_helpdiagrams_Result>("sp_helpdiagrams", diagramnameParameter, owner_idParameter);
    }

    public virtual int sp_renamediagram(string diagramname, Nullable<int> owner_id, string new_diagramname)
    {
        var diagramnameParameter = diagramname != null ?
            new ObjectParameter("diagramname", diagramname) :
            new ObjectParameter("diagramname", typeof(string));

        var owner_idParameter = owner_id.HasValue ?
            new ObjectParameter("owner_id", owner_id) :
            new ObjectParameter("owner_id", typeof(int));

        var new_diagramnameParameter = new_diagramname != null ?
            new ObjectParameter("new_diagramname", new_diagramname) :
            new ObjectParameter("new_diagramname", typeof(string));

        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction("sp_renamediagram", diagramnameParameter, owner_idParameter, new_diagramnameParameter);
    }

    public virtual int sp_upgraddiagrams()
    {
        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction("sp_upgraddiagrams");
    }
}