title: update customer custom fields from SCA or SSP
body: <p>I'm trying to update a custom entity field during registration in an SCA app.</p>
  
  <p>the published Netsuite docs indicate I should be able to call:</p>
  
  <pre><code>var webStore = session.getSiteSettings(['displayname', 'id']);
  customer = session.getCustomer();
  customer.updateProfile({
  internalid: internalid,
  customfields: {
      custentity_registered_site: webstore.id
  }
  });
  </code></pre>
  
  <p>but this throws the ever helpful UNEXPECTED_ERROR</p>
  
  <p>Has anyone had this working for custom fields? I am doing this just after registration so that may be the issue though I can get a valid customer internalid. Any luck with alternate syntax of some sort?</p>