title: Validation of viewstate with GetCompiledPageInstance
body: <p>on Default.aspx I wrote this code it succesfully shows me Webform1.aspx but it has also one button when I click on that button it give me error</p>
  
  <pre><code>protected void Page_Load(object sender, EventArgs e)
      {
          var pageView = PageParser.GetCompiledPageInstance("~/WebForm1.aspx", Server.MapPath("~/WebForm1.aspx"), HttpContext.Current);
          (pageView).ProcessRequest(HttpContext.Current);
  
      }
  </code></pre>
  
  <p><strong>Error on button click</strong></p>
  
  <pre><code>Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that &lt;machineKey&gt; configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster. 
  </code></pre>