Create really simple php script that use simplexml_load_string function, I used this one:

<?php
$xml = '<?xml version="1.0" encoding="UTF-8" ?>
<root>
</root>';
$temp = simplexml_load_string($xml, "SimpleXMLElement", LIBXML_NOERROR);
echo "It works?";
?>

Start debugger in Eclipse i.e. by pointing to script's url and start remote debugging session (I do it with Firefox easyXdebug ext). Do "Step Into" till you reach simplexml line. After you run it you'll let "Unexpected termination of script, debugging ended".

Screenshot: http://grab.by/bYnk