java postgresql ERROR: cached plan must not change result type

Question

I'm having a weird problem on my application, I'm receiving this error on one of my query's:

SEVERE: java.sql.SQLException: ERROR: cached plan must not change result type.

I only get this error in my production environment.

I can't find anything wrong or different, except that in the developer environment I'm using a maven jetty:run to start the app (Maven 3.3.9), and in production I have an Apache Tomcat v.8.0.30. The java version on my development environment is a little more updated 1.8.0_73 vs 1.8.0_71-b15 in production, that's all.

For a moment I believed it was my database, but then the problem should show up in both production and developer, but that's not happening only production is affected.

My database is on a PostgreSQL 9.4.9.

Thank you in advance.

******** EDIT *******

I did checkout this link: Postgres 8.3: "ERROR: cached plan must not change result type" but I have no scripts altering my tables or its columns.

***** EDIT 2 *****

I add the code:

static public ArrayList<OKCalendarEvent> listAllEventsByCalendarAndStatusBetween(String idCalendar,
                                                                                     Timestamp from,
                                                                                     Timestamp to,
                                                                                     OKCalendarEventStatus status  ,
                                                                                     WDataSource ds) throws OklexDataException {
        ArrayList<OKCalendarEvent> events = new ArrayList<>();

        String sql = "SELECT  " +
                " e.idreg ," +
                " e.calendar_id ," +
                " e.event_processid, " +
                " e.event_fieldid, " +
                " e.event_code," +
                " e.event_name ," +
                " e.event_description ," +
                " e.user_id ," +
                " e.event_start ," +
                " e.event_end ," +
                " e.event_duration ," +
                " e.event_status ," +
                " e.event_type ," +
                " e.event_buffer ," +
                " e.tfc ,  "+
                " e.id_event_origin ," +  //20160729
                " e.frequencyType ," + //20160729
                " e.frequencyEnd ," + //20160729
                " e.invitees, " + //20160729
                " (u.firstname ||' ' || u.lastname) as fullUserName " + //20160802
                "FROM ok_calendar_event e  " +
                "LEFT JOIN ok_user u " +
                "ON  e.user_id=u.userid " +
                "WHERE e.calendar_id = ? AND e.event_status = ?  AND e.event_start BETWEEN ? AND ?;";

        try {


            List<Object[]> rs = WData.doQuery(ds, sql, idCalendar,  status.getEventStatus(),  from, to);

            for (Object[] obj : rs) {

                OKCalendarEvent event = new OKCalendarEvent();

                event.setIdreg(NumberUtils.parseToInt(obj[0].toString()));
                event.setCalendarId(obj[1].toString());
                event.setIdProcess(NumberUtils.parseToLong(obj[2].toString()));
                event.setFieldId(obj[3].toString());
                event.setCode(obj[4].toString());
                event.setName(obj[5].toString());
                event.setDescription(obj[6].toString());
                event.setUserId(obj[7].toString());
                event.setStart(CalendarUtils.stringToTimeStamp(obj[8].toString(), Constants.dateTimeFormat));
                event.setEnd(CalendarUtils.stringToTimeStamp(obj[9].toString(), Constants.dateTimeFormat));
                event.setDuration(NumberUtils.parseToInt(obj[10].toString(), 0));
                event.setStatus(NumberUtils.parseToInt(obj[11].toString(), 0));
                event.setType(NumberUtils.parseToInt(obj[12].toString(), 0));
                event.setBuffer(obj[13].toString());
                event.setTfc(CalendarUtils.stringToTimeStamp(obj[14].toString(), Constants.dateTimeFormat));
                //20160729
                event.setId_event_origin( NumberUtils.parseToInt(obj[15].toString())  );
                event.setFrequency_type( NumberUtils.parseToInt(obj[16].toString())  );
                if(obj[17]!=null) {
                    event.setFrequency_end(CalendarUtils.stringToTimeStamp(obj[17].toString(), Constants.dateTimeFormat));
                }
                event.setInvitees(obj[18].toString());
                event.setUserFullName(obj[19].toString());

                events.add(event);
            }
        } catch (Exception e) {

            // process = new ArrayList<Process>();
            log.error(" | listAllEventsByCalendarAndStatusBetween |  failed, cause: "+ e.toString());
            throw new OklexDataException("There was a problem retrieving the OKCalendar list from the database.", e);
        }
        return events;
    }