AtmosException{errorCode=0, httpCode=500}

Trying to create a subtenant. Getting an AtmosException with errorCode=0. Any idea why?

Sample Code :

AtmosConfig config = null;
  try {
   config = new AtmosConfig("", "", new URI(""));  //removed the credential here for safety.

    AtmosApi atmos = new AtmosApiClient(config); 
    //ServiceInformation si = atmos.getServiceInformation(); 
    CreateSubtenantRequest req = new CreateSubtenantRequest(); 
    String subtenantId = atmos.createSubtenant(req);
    System.out.println("subtenantId :: "+subtenantId);
   
    //String stringContent = "Hello World!"; 
    //ObjectId oid1 = atmos.createObject( stringContent, "text/plain" ); 

  } catch (URISyntaxException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } 

Exception :

Exception in thread "main" AtmosException{errorCode=0, httpCode=500} com.emc.atmos.AtmosException: Internal Server Error

      at com.emc.atmos.api.jersey.ErrorFilter.handle(ErrorFilter.java:44)

      at com.emc.atmos.api.jersey.RetryFilter.handle(RetryFilter.java:51)

      at com.emc.atmos.api.jersey.AuthFilter.handle(AuthFilter.java:41)

      at com.sun.jersey.api.client.Client.handle(Client.java:652)

      at com.sun.jersey.api.client.WebResource.handle(WebResource.java:682)

      at com.sun.jersey.api.client.WebResource.access$200(WebResource.java:74)

      at com.sun.jersey.api.client.WebResource$Builder.put(WebResource.java:529)

      at com.emc.atmos.api.jersey.AtmosApiClient.createSubtenant(AtmosApiClient.java:712)

      at com.emc.oil.AtmosCreateSubtenant.main(AtmosCreateSubtenant.java:21)