use-ajaxerror.xml

<note id="use-ajaxerror" type="additional">
	<desc>If a request with %title% returns an error code, it will fail silently unless the script has also called the global <a href="http://api.jquery.com/ajaxError/">.ajaxError() </a> method. Alternatively, as of jQuery 1.5, the <code>.error()</code> method of the <code>jqXHR</code> object returned by %title% is also available for error handling.
	</desc>
</note>