[given that you have to debug this on your side, my goal here is to step you through the process].
Note: turn off combine/compress when debugging JavaScript, and make sure the Cache is also off - all on Performance tab of web server.
The key attribute on the html is data-do. It's a signal to the JavaScript to add some functionality to the element. In this case;
data-do="export"
So your next step is to open \web\scripts\jquery.nt-browse.js
if you search that for data-do="export" you'll find the line;
$(this.element).off('click.bt','[data-do="export"]')
.on('click.bt','[data-do="export"]',function(e){_this.exportTo('excel',this);});
basically this is "binding" the function exportTo to this button.
search for exportTo. there are a cluster of 3 funtions here that work together. exportTo, exportProgress and setTimer. You can add lines
console.log('something')
as a debugging tool to make stuff appear in the firebug console.
your goal is to see if the call to ntbrowse.timer is made. You might want to inspect the value of this.options.divId. Obviously you should compare what happens in the working example with what happens in your app.
Cheers
Bruce