เจอ Error There is already an open DataReader associated with this Connection which must be closed first. C# MVC มือใหม่ครับ

public List<ItemMasterView> GetAllItemLists()
{
    List<ItemMasterView> ItemViews = new List<ItemMasterView>();
    using (packinglistEntities db = new packinglistEntities())
    {
        ItemMasterView IMV;
        var items = (from c in db.itemmaster
		select c).ToList()

        foreach (itemmaster u in db.itemmasters)
        {
            IMV = new ItemMasterView();
            IMV.ItemID = u.ItemID;
            IMV.ItemName = u.ItemName;
            IMV.ItemDesc = u.ItemDesc;

            IMV.Weight = u.Weight;
            IMV.Height = u.Height;
            IMV.Width = u.Width;
            IMV.StartDate = IMV.StartDate;
            IMV.EndDate = IMV.EndDate;

            var ILU = db.itemlookuptypes.Find(u.ItemLookUpID);
            if (ILU != null)
            {
                IMV.Name = ILU.Name;
            }
            /*IMV.Name = "JM";*/
            


            ItemViews.Add(IMV);
        }
    }

    return ItemViews;
}

public List<ItemMasterView> GetAllItemLists()
{
    List<ItemMasterView> ItemViews = new List<ItemMasterView>();
    using (packinglistEntities db = new packinglistEntities())
    {
        var IMV  = (from c in db.itemmaster
		select new ItemMasterView
		{
		    ItemID = c.ItemID;
		    ItemName = c.ItemName;
		    ItemDesc = c.ItemDesc;
		    Weight = c.Weight;
		    Height = c.Height;
		    Width = c.Width;
		    StartDate = c.StartDate;
		    EndDate = c.EndDate;	
		}).ToList()
    }

    return ItemViews;
}