php webservice错误

系统：win7 xampp3.2.1
extension=php_soap.dll已经开启打开
网上下载webservice实例（加载wsdl）都出现DTD are not supported by SOAP的错误。非加载wsdl模式可以运行。这个是什么原因呢？
<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:tns="http://www.somelocation.com" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns="http://schemas.xmlsoap.org/wsdl/" targetNamespace="http://www.somelocation.com">
<types>
<xsd:schema targetNamespace="http://www.somelocation.com">
<xsd:import namespace="http://schemas.xmlsoap.org/soap/encoding/" />
<xsd:import namespace="http://schemas.xmlsoap.org/wsdl/" />
</xsd:schema>
</types>
<message name="userDataRequest">
  <part name="operation" type="xsd:string" />
  <part name="statement" type="xsd:string" />
</message>
<message name="userDataResponse">
  <part name="return" type="xsd:string" />
</message>
<portType name="userWsdlPortType">
  <operation name="userData">
    <documentation>Query User Data</documentation>
    <input message="tns:userDataRequest" />
    <output message="tns:userDataResponse" />
  </operation>
</portType>
<binding name="userWsdlBinding" type="tns:userWsdlPortType">
  <soap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http" />
  <operation name="userData">
    <soap:operation soapAction="http://www.somelocation.com#feelbad" style="rpc" />
    <input><soap:body use="encoded" namespace="http://www.somelocation.com" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" /></input>
    <output><soap:body use="encoded" namespace="http://www.somelocation.com" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" /></output>
  </operation>
</binding>
<service name="userWsdl">
  <port name="userWsdlPort" binding="tns:userWsdlBinding">
    <soap:address location="http://localhost/soap/user.php" />
  </port>
</service>
</definitions>