title: Resolution failed with error: No public constructor is available
body: <p>I am using WCF web services and it was using OLD unity 2.0. So i updated Unity and other reference with latest version 5.0.  I am getting exception: </p>
  
  <pre><code>Resolution failed with error: No public constructor is available for type xyz.Services.Contracts.Security.IAuthenticationService.
  
  For more detailed information run Unity in debug mode: new UnityContainer().AddExtension(new Diagnostic())
  
  Exception of type 'Unity.Exceptions.InvalidRegistrationException' was thrown.
  </code></pre>
  
  <p>Really i tried many things but not success. please any expert have a look.</p>