title: java.io.NotSerializableException: java.util.HashMap$Values
body: <p>Stacktrace:</p>
  
  <pre><code>org.jboss.remoting.InvocationFailureException: Unable to perform invocation;
  nested exception is: java.io.WriteAbortedException: writing aborted;
  java.io.NotSerializableException: java.util.HashMap$Values
  </code></pre>
  
  <p>Sadly, the log doesn't show the line or the class where the serialization problem occurs, but debugging the ESB until the step where problem occurs all the HashMap's that are used have only Serializable objects like String, Long and Date!</p>
  
  <p>Also, the problem occurs when calling a remote method, which is void.</p>
  
  <p>Have you seen something like this before?</p>