SOAP response is not parsed anymore (maybe after adding namespace)

We are communication with an ERP interface from a Webshop. The ERP part got upgraded.

Now the response is not parsed properly anymore.

I am using the PHP SOAP client in WSDL mode.

protected function getSoapClient()
{
    $context = // ...

    $client = new \SoapClient($this->url . '?wsdl', [
        'trace' => true,
        'stream_context'  => $context,
        // 'uri' => 'urn:example-org:WebshopService',
    ]);

    return $client;
}

$client = $this->getSoapClient();
$response = $client->placeOrder($placeOrder);

Using getLastResponse I see the following result:

$client->__getLastResponse();
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
    <soap:Body>
        <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
                          xmlns:web="urn:example-org:WebshopService">
            <soapenv:Header/>
            <soapenv:Body>
                <web:placeOrderResponse>
                    <web:result>OK</web:result>
                </web:placeOrderResponse>
            </soapenv:Body>
        </soapenv:Envelope>
    </soap:Body>
</soap:Envelope>

In an earlier version of the ERP system it worked and $response was an instance of \StdClass. Now $response is null.

I believe this is because the namespaces were introduced in the result.

I tried adding the line

 'uri' => 'urn:example-org:WebshopService',

to the SOAP config but it did not help.

Is this likely a parsing problem of the result? How can it be fixed? Of course I could simple look into last response from the trace, but I believe a better solution would be if the SOAP client parses the result properly.

As per PiTheNumber's answer I also tried

'soap_version' => SOAP_1_2,

But getting

 A SOAP 1.2 message is not valid when sent to a SOAP 1.1 only endpoint.  

When using

 'uri' => 'http://schemas.xmlsoap.org/soap/envelope/',

response is still null.

maybe my WSDL is wrong ... https://stackoverflow.com/a/26056248/288568

<schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:tns="urn:example-org" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:prodata="urn:schemas-progress-com:xml-prodata:0001" xmlns:S2="urn:example-org:WebshopService" xmlns:S1="urn:soap-fault:details" xmlns="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" targetNamespace="urn:example-org:WebshopService">
  <element name="placeOrder">
    <complexType>
      <sequence>
    <element name="pcRequest" nillable="true" type="xsd:string"/>
    <element name="gpcBCR_Connection_Obj" nillable="true" type="xsd:string"/>
      </sequence>
    </complexType>
  </element>
  <element name="placeOrderResponse">
    <complexType>
      <sequence>
    <element name="result" nillable="true" type="xsd:string"/>
      </sequence>
    </complexType>
  </element>
</schema>

Edit2:

I found https://stackoverflow.com/a/22717640/288568 and checked whether the WSDL defined the return value as void, it doesn't:

var_dump($client->__getFunctions());

Returns

array(1) {
  [0]=>
  string(53) "placeOrderResponse placeOrder(placeOrder 
$parameters)"
}

EDIT3:

I tried somthing else:

I used the ReadyAPI trial version to mock the SOAP API based on the WSDL I receive from the actual ERP.

When I do you, the result looks like this:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:proalpha-org:WebshopService">
   <soapenv:Header/>
   <soapenv:Body>
      <urn:placeOrderResponse>
     <urn:result>OK</urn:result>
      </urn:placeOrderResponse>
   </soapenv:Body>
</soapenv:Envelope>

Which is properly parsed by PHP.

This is the Diff:

So either the WSDL is not 100% correct or leaves room for different interpretation?

Is there something wrong with the SOAP server? Is it violating standards? Or is this a bug in the PHP Soap client?

https://www.ibm.com/docs/en/cics-ts/5.4?topic=format-structure-soap-message reads like

The SOAP envelope The SOAP is the root element in every SOAP message. It contains two child elements, an optional , and a mandatory > .

So it seams the envolpe should only appear once as root, not twice?