"Call Web Service" Action Works for Test But Not During Workflow Runtime

 

The issue we are having is with calling a SOAP web service operation with the "Call Web Service" action in the workflow. The web operation DOES return a correct SOAP response when we call it from the "Run Now" window. However, it DOESN'T return a correct SOAP response during the running of the workflow.

 

The error message logged from the "Store error text in" output says:

 

Error: Namespace prefix 'soap' is not defined.

 

We also logged the SOAP response from the Web Service call during the running of the workflow and had this response:

 

<a:ErrorMessage i:nil="true"   xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:a="http://schemas.datacontract.org/2004/07/EOrderingServices" />
<a:HttpStatusCode i:nil="true" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:a="http://schemas.datacontract.org/2004/07/EOrderingServices" />
<a:StackTrace i:nil="true"     xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:a="http://schemas.datacontract.org/2004/07/EOrderingServices" />
<a:StatusDescription i:nil="true" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:a="http://schemas.datacontract.org/2004/07/EOrderingServices" />
<a:Successful                  xmlns:a="http://schemas.datacontract.org/2004/07/EOrderingServices">true</a:Successful>
<a:Result            xmlns:a="http://schemas.datacontract.org/2004/07/EOrderingServices"> true</a:Result>

 

This response isn't correct, and should match the below response that was returned from the test call in the "Run Now" page.

 

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
  <s:Body>
    <IsWaiverRequiredResponse xmlns="http://tempuri.org/">
      <IsWaiverRequiredResult xmlns:a="http://schemas.datacontract.org/2004/07/EOrderingServices" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
        <a:ErrorMessage i:nil="true" />
        <a:HttpStatusCode i:nil="true" />
        <a:StackTrace i:nil="true" />
        <a:StatusDescription i:nil="true" />
        <a:Successful>true</a:Successful>
        <a:Result>true</a:Result>
      </IsWaiverRequiredResult>
    </IsWaiverRequiredResponse>
  </s:Body>
</s:Envelope>

 

We're not sure why the SOAP responses differ when calling the operation from the test window and during the workflow runtime when the settings should be the same. We can successfully call the same service operation with WCF elsewhere from C# applications. Does anyone have an idea of what might be happening in the Nintex "Call Web Service" activity during the workflow? I can give more info about the settings if needed.