form with input file not submitted when using bootstrapFileInput - php

Question

I am submitting a form which contains some text field, dropdown and a file input. The form is submitted using JQuery/Ajax and the data is sent to php. If I submit the form without using bootstrapFileInput, all the data of the form is sent to php and correctly processed but as soon as I enable bootstrapFileInput, the input file is missing while all other fields are correctly submitted.
I get no error in the console.
HTML :
<div class="form-inline">
<div id="singUser">
<form role="form" name="setLimit" id="setLimit" class="form-inline" enctype="multipart/form-data">
<input type="text" id="userid" name="userid" class="form-control" placeholder="Enter User ID">
<input type="text" id="quota" name="quota" class="form-control" placeholder="Enter Quota limit in GB">
<select class="form-control" id="ltype" name="ltype">
<option value="desktop">Desktop</option>
<option value="server">Server</option>
</select>
<input type="checkbox" id="rmlimit" name="rmlimit"> Remove Limit (Set to Shared storage)
<button type="submit" id="sgUserButn" class="btn btn-default btn-primary" >Set Limit!</button>
</div>
<span id="multUser">
<p>Select a file with a list of user ids and the limit in GB you wish to assign download the example file.</p>
<img src="img/csvex.png" id="csvexp" ><br><br>
<input class="file-input-wrapper" type="file" id="lsUsers" name="lsUsers" data-filename-placement="inside" title="Select CSV File">
<button id="mulUserButn" type="submit" class="btn btn-default btn-primary" >Set Limit!</button>
</span>
</form>
</div>
JQuery
$(document).ready(function() {
$.ajaxSetup({
cache: false
});
$('input[type=file]').bootstrapFileInput();
$('.file-inputs').bootstrapFileInput();
$('#setLimit')
.submit(function(e) {
busyStatus();
$.ajax({
url: 'testProcess.php',
type: 'POST',
data: new FormData(this),
processData: false,
contentType: false,
complete: function() {
idleStatus();
},
success: function(result) {
//$(document.body).append(result);
//alert( $(result).toArray() );
$("#result").html(result);
}
});
e.preventDefault();
return false;
});
});
PHP
<?php
print_r($_POST);
echo '<br>';
print_r($_FILES);
?>
I am really out of ideas and would really appreciate some help.
Thanks in advance.