title: Trouble talking to web service in C#: XmlChoiceIdentifierATtribute is not valid in Items
body: <p>There is a <a href="http://en.wikipedia.org/wiki/Web_Services_Description_Language" rel="nofollow">WSDL</a> webservice that is out of my control that I'm having trouble with; I can interact with this service using <a href="http://en.wikipedia.org/wiki/SoapUI" rel="nofollow">soapUI</a> and using Add Service Reference -> advanced -> Add Web Reference without a problem.</p>
  
  <p>However, when I attempt to talk to it using the standard Add Service Reference method (add a service reference, connect using the generated code from wsdl.exe), I get the following error:</p>
  
  <blockquote>
    <p>XmlSerializer attribute System.Xml.Serialization.XmlChoiceIdentifierAttribute is not 
        valid in Items. Only XmlElement, XmlArray, XmlArrayItem, XmlAnyAttribute and 
        XmlAnyElement attributes are supported when IsWrapped is true.</p>
    
    <p>Description: An unhandled exception occurred during the execution of the current web 
        request. Please review the stack trace for more information about the error and where 
        it originated in the code. </p>
    
    <p>Exception Details: System.InvalidOperationException: XmlSerializer attribute 
        System.Xml.Serialization.XmlChoiceIdentifierAttribute is not valid in Items. Only 
        XmlElement, XmlArray, XmlArrayItem, XmlAnyAttribute and XmlAnyElement attributes are
        supported when IsWrapped is true.</p>
  </blockquote>
  
  <p>I've read some things saying there is some SOAP incompatibility between Java and .NET, but searching around I can find virtually no one who is having this problem, making me think I must be doing something wrong?</p>