With jQuery version 3 the function load and the event onload are handled differently.
So in your code you need to write:
$(window).on('load', function (e) {
For details take a look to jQuery 3.0:
Removed deprecated event aliases
.load, .unload, and .error, deprecated since jQuery 1.8, are no more. Use .on() to register listeners.
Because Bootstrap v3 is not compatible with jQuery v3 (refer to bootstrap issues 16834) I changed to jQuery 1.x in my snippet.
My snippet:
$(window).on('load', function (e) {
$('#MyButton').on('click', function (e) {
alert('clicked')
$("#div").load(" #div > *");
});
});<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<button id="MyButton" class="btn btn-warning">Refresh</button>
<div class="col-md-3" id="div">
<div class="alert alert-warning alert-dismissible fade in" role="alert">
<button type="button" class="close" data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
<strong>Holy guacamole!</strong>
</div>
<div class="alert alert-danger alert-dismissible fade in" role="alert">
<button type="button" class="close" data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
<strong>Holy guacamole!</strong>
</div>
<div class="alert alert-success alert-dismissible fade in" role="alert">
<button type="button" class="close" data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
<strong>Holy guacamole!</strong>
</div>
</div>