Hi, 
I want to display modal popup in the system. When i tried the modal in jsfiddle it worked, but when in my system, the modal become invisible but when i check inspect element the modal is exist. The class of modal that i use is modal fade, but when i change to modal it work just the background is dark not fade. 
I change from 4.3.1 to 4.4.0
How to solve this issue? 
<a href="" class="btn btn-info" data-toggle="modal" data-target="#myModal2">Update</a>
<div class="modal fade" id="myModal2" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
    <div class="modal-dialog">
        <div class="modal-content">
            @using (Html.BeginForm("UpdateApt", "Home", FormMethod.Post, new { @class = "form-horizontal", role = "form", enctype = "multipart/form-data" }))
            {
                <div class="modal-header">
                    <h5 class="modal-title custom_align">New message</h5>
                    <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                        <span aria-hidden="true">×</span>
                    </button>
                </div>
                <div class="modal-body">
                    <div class="form-group">
                        <input type="hidden" id="hfMaterialId" name="Id" value="" />
                        <span>Selection: </span>
                        <input class="form-control " id="Requester_id" name="Requester_id" type="text" value="">
                    </div>
                    <div class="form-group">
                        <span>System :</span>
                        <input class="form-control " id="admComment" name="admComment" type="text" value="">
                    </div>
                </div>
                <div class="modal-footer">
                    <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
                    <button type="submit" class="btn btn-success">Save</button>
                </div>
            }
        </div>
    </div>
</div>
 
$(function () {
    $('#myModal2').on('show.bs.modal', function (e) {
        $('#myModal2').focus();
    })
});