title: Unity 3 - The type name or alias xxxx could not be resolved
body: <p>I've read through several related questions here and I still can't seem to get my Unity XML configuration to work.</p>
  
  <p>Here is my configuration file ...</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;unity xmlns="http://schemas.microsoft.com/practices/2010/unity"&gt;
      &lt;assembly name="System.Security" /&gt;
      &lt;namespace name="System.Security.Cryptography" /&gt;
      &lt;container name="Default"&gt;
          &lt;register type="HashAlgorithm" mapTo="SHA256Managed" /&gt;
          &lt;register type="SymmetricAlgorithm" mapTo="AesCryptoServiceProvider" /&gt;
      &lt;/container&gt;
  &lt;/unity&gt;
  </code></pre>
  
  <p>And the error message I get is ...</p>
  
  <blockquote>
    <p>The type name or alias <strong>AesCryptoServiceProvider</strong> could not be resolved.
    Please check your configuration file and verify this type name.</p>
  </blockquote>
  
  <p>The HashAlgorithm is resolving normally, just not the AES provider.</p>
  
  <p>The <strong>System.Security</strong> assembly is referenced in my project, and the <strong>SymmetricAlgorithm</strong> type can be resolved if I do ...</p>
  
  <pre><code>IUnityContainer Container = new UnityContainer ();
  
  Container.RegisterType&lt;SymmetricAlgorithm, AesCryptoServiceProvider&gt; ();
  </code></pre>
  
  <p>... but I'd like to keep the configuration out of the code if possible.</p>
  
  <p>Can anyone help me out with this?</p>