Hi Rui,
I have a TON of of javaScript & jQuey in there. I stripped it all out to test your code. Here is what I am working with right now:
$(document).ready(function(){
var filesList = [];
$('.fileuploader').on('updatevalidation', function(){
filesList = [];
$('.myUpload').each(function(){
$(this).find('.file').each(function(){
var file = {}
file.title = $(this).find('td:eq(0) a').attr('title');
file.href = $(this).find('td:eq(0) a').attr('href');
file.size = $(this).find('td:eq(1) div').text();
file.aid = $(this).find('.delCell div').attr('aid');
filesList.push(file);
});
});
var html = '<table class="files"><colgroup><col width="80%"><col width="15%"><col width="5%"></colgroup><tbody>';
_.each(filesList, function(file){
html += '<tr class="file"><td><a target="_blank" download="" title="' + file.title + '" class="ellipsis" href="'+file.href+'">'+file.title+'</a></td><td><div>'+file.size+'</div></td><td class="delCell"><div onclick="DeleteFile('+file.aid+')" class="selectable lfi-times" title="Delete">×</div></td></tr>';
});
html += '</tbody></table>';
$('.customHTML').html(html);
});
});
function DeleteFile(aid) {
$('.file-del[aid="'+aid+'"]').click();
}
^I pasted in your code with no changes.
Also, I removed the 'required field' setting on the upload button.
Here is what is happening:
I can upload a file with no 'value is required' error mssage:

But it does not appear in my custom HTML field. So it seems like it is not triggering properly.
I swapped out the updatevalidation with click to test and the upload will appear in im customHTML field:

On clicking the 'X' to delete, nothing happens now. Probably because I have the DeleteFile outside of the document.ready. (Sorry about that before!)
Tell me what you need to see and I'll send it over.
Thanks Rui for your patience dealing with the noobs!
Chris