title: 500.19 error with IIS7.5
body: <p>I am getting the following error, even after I unlock my website. Any reasons?</p>
  
  <p>HTTP Error 500.19 - Internal Server Error
  The requested page cannot be accessed because the related configuration data for the page is invalid.</p>
  
  <pre><code>Module         CustomErrorModule
  Notification   SendResponse
  Handler        StaticFile
  Error Code     0x80070021
  Config Error   Lock violation
  Config File    \\?\C:\Web\En\web.config
  
  &lt;validation validateIntegratedModeConfiguration="false"/&gt;
  &lt;httpErrors errorMode="DetailedLocalOnly" defaultPath="/Oops.aspx" defaultResponseMode="ExecuteURL"&gt;
  &lt;clear&gt;&lt;/clear&gt;
  </code></pre>
  
  <p>I have done the following in applicationHost.config</p>
  
  <pre><code>&lt;location path="mysite.net" overrideMode="Allow"&gt;
      &lt;system.webServer&gt;
          &lt;handlers /&gt;
          &lt;httpErrors /&gt;
      &lt;/system.webServer&gt;
  &lt;/location&gt;
  </code></pre>