Could not find a part of the path 'E:\\highlighted\\highlighted\\db\\'

foreach (GridViewRow row in grdCustomer.Rows)
            {

                var isChecked = (row.FindControl("CheckBox1") as CheckBox);
                if (isChecked.Checked)
                {
                    string filename = (row.FindControl("lblFileName") as HyperLink).Text;




                    byte[] bytes;

                    string fileName, contentType, version;
                    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
                    using (SqlConnection con = new SqlConnection(constr))
                    {
                        using (SqlCommand cmd = new SqlCommand())
                        {
                            cmd.CommandText = "select uploadfilename,filename, Description, version,ContentType from upload_test where filename=@filename";
                            cmd.Parameters.AddWithValue("@filename", filename);
                            cmd.Connection = con;
                            con.Open();
                            using (SqlDataReader sdr = cmd.ExecuteReader())
                            {
                                sdr.Read();
                                bytes = (byte[])sdr["Description"];
                                contentType = sdr["ContentType"].ToString();
                                fileName = sdr["uploadfilename"].ToString();
                                version = sdr["version"].ToString();

                                // string dateString = DateTime.Now.ToString("");



                            }
                        }




                        //string path = HttpContext.Current.Server.MapPath("~/" + version + "/");
                        //Directory.CreateDirectory(path);
                        ////FileAttributes att = File.GetAttributes(path);
                        ////File.SetAttributes(path,att);

                        //DirectorySecurity sec = Directory.GetAccessControl(path);
                        //var appDataPath = Server.MapPath("~/db/");

                        //if (!Directory.Exists(appDataPath))
                        //{
                        //    Directory.CreateDirectory(appDataPath);
                        //}



                        Response.Clear();
                            Response.Buffer = true;

                            Response.Charset = "";
                            Response.Cache.SetCacheability(HttpCacheability.NoCache);
                            Response.ContentType = contentType;

                            Response.AppendHeader("Content-Disposition", string.Format("attachment; filename={0}", filename));
                            Response.BinaryWrite(bytes);
                        //string id = path + filename + contentType;

                        Response.TransmitFile(HttpContext.Current.Server.MapPath("~/db/"));


                        //Response.WriteFile(path);
                        Response.End();