Call to a member function item() on null

[cptpiper]

Good day!
I use your project to understand xmlrpc. So in my experiments i get the answer from xmlrpc server:

I tried to use converter on it but there was error
$objConv = new \Milo\XmlRpc\Converter();
var_dump($objConv->fromXml($strXml));

Call to a member function item() on null (0)
/home/bitrix/vendor/milo/xml-rpc/src/XmlRpc/Coder.php:252