title: ASP.NET 4 URL limitations: why URL cannot contain any %3f characters
body: <pre><code>http://site.com/page%3fcharacter
  </code></pre>
  
  <p>This URL will return the following error:</p>
  
  <pre><code>Illegal characters in path.
  </code></pre>
  
  <p>I'm already put this in web.config:</p>
  
  <pre><code>&lt;system.web&gt;
  &lt;httpRuntime requestValidationMode="2.0" requestPathInvalidCharacters="" /&gt;
  &lt;pages validateRequest="false"&gt; 
  ...
  </code></pre>
  
  <p>How can I fix this error?</p>