jQuery.Deferred exception: Cannot read property 'on' of undefined TypeError: Cannot read property 'on' of undefined
at initCustomDropdown (http://localhost/wordpress/wp-content/themes/****/lib/js/custom.js:116:15)
at HTMLDocument.<anonymous> (http://localhost/wordpress/wp-content/themes/****/lib/js/custom.js:45:2)
at l (http://localhost/wordpress/wp-content/themes/jessica/lib/js/jquery-3.3.1.min.js:2:29375)
at c (http://localhost/wordpress/wp-content/themes/****/lib/js/jquery-3.3.1.min.js:2:29677) undefined

function initCustomDropdown()
{
    if($('.custom_dropdown_placeholder').length && $('.custom_list').length)
    {
        var placeholder = $('.custom_dropdown_placeholder');
        var list = $('.custom_list');
    }

    placeholder.on('click', function (ev)
    {
        if(list.hasClass('active'))
        {
            list.removeClass('active');
        }
        else
        {
            list.addClass('active');
        }

        $(document).one('click', function closeForm(e)
        {
            if($(e.target).hasClass('clc'))
            {
                $(document).one('click', closeForm);
            }
            else
            {
                list.removeClass('active');
            }
        });

    });

    $('.custom_list a').on('click', function (ev)
    {
        ev.preventDefault();
        var index = $(this).parent().index();

        placeholder.text( $(this).text() ).css('opacity', '1');

        if(list.hasClass('active'))
        {
            list.removeClass('active');
        }
        else
        {
            list.addClass('active');
        }
    });


    $('select').on('change', function (e)
    {
        placeholder.text(this.value);

        $(this).animate({width: placeholder.width() + 'px' });
    });
}

initCustomDropdown();
initPageMenu();
initDealsSlider();
initTabLines();
initFeaturedSlider();
featuredSliderZIndex();
initPopularSlider();
initBanner2Slider();
initFavs();
initArrivalsSlider();
arrivalsSliderZIndex();
bestsellersSlider();
initTabs();
initTrendsSlider();
initReviewsSlider();
initViewedSlider();
initBrandsSlider();
initTimer();