title: "Validation of viewstate MAC failed" on postback to a different page
body: <p>I'm working on a web form which works fine as long as it posts back to itself. In Reports.aspx I have:</p>
  
  <pre><code>&lt;form runat="server" method="post"&gt;
  </code></pre>
  
  <p>but, when I try to get it to post to a different page:</p>
  
  <pre><code>&lt;form runat="server" method="post" action="DisplayReport.aspx"&gt;
  </code></pre>
  
  <p>I get the "Validation of viewstate MAX failed" error. I've tried setting the machine key and disabling the viewstate in web.config, but nothing seems to help. Am I stuck posting back to the same page? If so what is the point of the action attribute?</p>