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$('modalId').modal('hide');
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$(window).on('popstate', function() {
$(".modal-backdrop").remove();
});
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$('body').removeClass('modal-open');
$('.modal-backdrop').remove();
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//setting callback function for 'hidden.bs.modal' event
$('#modal').on('hidden.bs.modal', function(){
//remove the backdrop
$('.modal-backdrop').remove();
})