If is called
libxml_disable_entity_loader(true);
, it causes that new SoapClient(.) fails with
SOAP-ERROR: Parsing WSDL: Couldn't load from 'D:\path/dm_operations.wsdl' : failed to load external entity "D:\path/dm_operations.wsdl
because this wsdl imports a xsd as an another external file.
Tested on php 7.1.12, win x64.