Render_table on ORACLE with Timestamp: Error conv to String


I’ve just begun using DHTMLX java connectors and I am facing a problem when rendering Oracle Timestamp/Date fields.
I can render String and Numeric fields with no problem. But when I add a Timestamp or Date field it throws :

Here is my code, I am using a servlet for my webapp, it is configured by osgi blueprint to get the datasource from my smx server:

public class JournalState extends ThreadSafeConnectorServlet
   private static final long serialVersionUID = 1L;
   private static DataSource dataSource;
   public JournalState(final DataSource dataSourceServ) {
      dataSource = dataSourceServ;

   protected void configure(HttpServletRequest req, HttpServletResponse res){

      Connection conn = null;
         conn = dataSource.getConnection();
      }catch(Throwable e){

      JSONCommonConnector c = new JSONCommonConnector(conn, DBType.Oracle);
      c.servlet(req, res);

      c.render_table("MYTABLE", "ID", "DATE"); // THIS DATE is a Timestamp field, thus FAILS and throws the error

     // c.render_table("MYTABLE", "ID", "NAME, LOCATION, QUANTITY") // THESES are String and Numerics, it works

Any ideas?