Erro na formatação da data.

Não consigo saber o motivo do erro abaixo: java.util.GregorianCalendar[time=1514772300000,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="America/Sao_Paulo",offset=-10800000,dstSavings=3600000,useDaylight=true,transitions=129,lastRule=java.util.SimpleTimeZone[id=America/Sao_Paulo,offset=-10800000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=9,startDay=15,startDayOfWeek=1,startTime=0,startTimeMode=0,endMode=3,endMonth=1,endDay=15,endDayOfWeek=1,endTime=0,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2018,MONTH=0,WEEK_OF_YEAR=1,WEEK_OF_MONTH=1,DAY_OF_MONTH=1,DAY_OF_YEAR=1,DAY_OF_WEEK=2,DAY_OF_WEEK_IN_MONTH=1,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=5,SECOND=0,MILLISECOND=0,ZONE_OFFSET=-10800000,DST_OFFSET=3600000]

@Bean
    public FormattingConversionService mvcConversionService() {
        DefaultFormattingConversionService conversionService = new DefaultFormattingConversionService();
        DateFormatterRegistrar registrar = new DateFormatterRegistrar();
        registrar.setFormatter(new DateFormatter("dd/mm/yyyy"));
        registrar.registerFormatters(conversionService);

        return conversionService;        
    }