title: LinkedHashSet serialization excpetion in GWT Development Mode only
body: <p>I have the problem that I get this SerializationException </p>
  
  <p><code>com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException: The response could not be deserialized</code></p>
  
  <p><code>Caused by: com.google.gwt.user.client.rpc.SerializationException: java.util.LinkedHashSet/95640124</code></p>
  
  <p>but just in the Development Mode of GWT 2.7.0. If I compile the application and run it on the webserver (tomcat) it is working fine. Does anybody have an idea why this is the case?</p>
  
  <p>The object which causes the exception is the following:</p>
  
  <pre><code>import java.util.Collection;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.TreeSet;
  
  import com.google.gwt.user.client.rpc.IsSerializable;
  
  public class MyCustomObject implements IndexedContent, IsSerializable {
      //PLACEHOLDER
  }
  </code></pre>
  
  <p>I'm just receiving a list of MyCustomObject.</p>
  
  <p><strong>Why is it not working locally in Dev Mode but compiled on the server?</strong></p>