The jQuery UI datepicker previous/next buttons are not working after updating to 1.12.1 version

The jQuery UI datepicker previous/next buttons are not working after updating to 1.12.1 version

Hi all! Please, advice what things could lead to the broken buttons. Code wasn't change from it was written. 

function onDateChanged(y, m) {
    $('#calYear').val(y)
    $('#calMonth').val(m)
    $('#dataChanged').trigger('click');
}

function onDayChanged(date) {
    $('#calYear').val("0")
    $('#calMonth').val("0")
    $('#change').val(date)
    $('#dayChanged').trigger('click');
}

$( "#datepicker" ).datepicker({
    inline: true,
    beforeShowDay: nationalDays,
    dateFormat : 'dd/mm/yy',
    changeMonth : true,
    changeYear : true,
    minDate : '01/01/2007', 
    onChangeMonthYear : onDateChanged,
    defaultDate: new Date('<fmt:formatDate pattern="YYYY/MM/dd" value="${model.calendarModel.selectedDate}" />'),
    onSelect: function(dateText, inst) { 
        onDayChanged(dateText)
    }    
});