i faced the same problem , the solution worked for me , hope it will work for you too.
<script src="https://stackoverflow.com/questions/18345714/content/js/jquery.min.js"></script>
<script src="content/js/bootstrap.min.js"></script>
<script>
$(document).ready(function () {
$('.dropdown-toggle').dropdown();
});
</script>
Please include the “jquery.min.js” file before “bootstrap.min.js” file, if you shuffle the order it will not work.