title: Unable to serialize List<SelectListItem>
body: <p>I'm moving an existing MVC3 app from InProc to ASP.Net Session State service.
  One of the model objects has this property:</p>
  
  <pre><code>public List&lt;System.Web.Mvc.SelectListItem&gt; StateCodes { get; set; }
  </code></pre>
  
  <p>and it's throwing this error</p>
  
  <blockquote>
    <p>Unable to serialize the session state. In 'StateServer' and
    'SQLServer' mode, ASP.NET will serialize the session state objects,
    and as a result non-serializable objects or MarshalByRef objects are
    not permitted. The same restriction applies if similar serialization
    is done by the custom session state store in 'Custom' mode.</p>
  </blockquote>
  
  <p>Is there a way to get <code>List&lt;SelectListItem&gt;</code> to serialize?</p>