Invalid argument supplied for foreach() in

Invalid argument supplied for foreach() in

i keep getting the error for this code even though it works as it should
when i run it in browser, but when called by include_once it doesnt work
due to the error
foreach(($hostlist->uploaded) as $uploaded) {
knowing that the variables are as follows:
$config['hostlist'] = 'xml/host.xml';
$hostlist = simplexml_load_file($config['hostlist']);
thanks in advance