проблема в коде
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using - вопрос №1957773
using System; using System.Collections.Generic; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; { public partial class MasterPage: System.Web.UI.MasterPage { protected void Page_Load(object sender, EventArgs e) { } } }