title: What are possible causes of ErrorMessage: Dynamic Backend Host Not Specified?
body: <p>There is not much on SO about what to do when you are seeing <code>&lt;ErrorMessage&gt;Dynamic backend host not specified&lt;/ErrorMessage&gt;</code> except for <a href="https://stackoverflow.com/questions/34253933/python-requests-get-dynamic-backend-host-not-specified">this question.</a> </p>
  
  <p>Hoping this will become a resource for other developers who face this issue, as well as answer my specific case.</p>
  
  <p>I am trying to test that SOAP requests sent from my client (built from WSDL) can hit a server (generated from the same WSDL), the source code for which I have no access to or responsibility for.</p>
  
  <p>Currently I am just <code>curl</code>-ing against the server's endpoint with my (client) certificates and some XML to POST:</p>
  
  <pre><code> curl -X POST https://www.endpoint.com/service.svc:443 --cert     certificates.p12:password --cert-type pkcs12 -d ‘&lt;example&gt;Place Holder XML &lt;/example&gt;’
  </code></pre>
  
  <p>(Can't include the actual curl request due to its confidential nature)</p>
  
  <p>The server is responding with:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;ErrorMessage&gt;Dynamic backend host not specified&lt;/ErrorMessage&gt;
  </code></pre>
  
  <p>The other SO answer linked above suggests that this may be a result of not including the correct headers in my request. If this is the problem in my case, does anyone know why the lack of headers is the cause of trouble here? Are there other possible causes of this error that are the responsibility of the client? Could this be an error on the server?</p>