Failed to parse servers response: Unknown type: string

[Nimal Risken]

Hello together,

when i try to call the ping method from neos-server i get the following error 
code:
org.apache.xmlrpc.client.XmlRpcClientException: Failed to parse servers 
response: Unknown type: string


Code:
-----


import java.io.*;
import java.net.*;
import java.util.Vector;
import org.apache.xmlrpc.client.XmlRpcClientConfigImpl;
import org.apache.xmlrpc.client.XmlRpcClient;

public class XmlRPC{

public static void main(String[] agrs) throws Exception{
   XmlRpcClientConfigImpl konfig = new XmlRpcClientConfigImpl();
   konfig.setServerURL(new URL("http://neos.mcs.anl.gov:3332";));

   XmlRpcClient server = new XmlRpcClient();
   server.setConfig(konfig);

   //Parameter
   Object[] param = {};

   //Serverfunktion aufrufen
   System.out.println(server.execute("ping",param));
}

}