title: How to enable custom UI error messages on Dialog Popups in JHipster 4.13.2
body: <p>I'm loving the JHipster project, a big thank you to the team, its really a big time saver. I do however get a bit stuck on a few things. My latest issue is related to getting custom error alerts on the UI pages, specifically the dialog popups - doing create, delete, custom operations etc.</p>
  
  <p>To replicate the issue, create any entity or go into the UserResource.delete() or createUser() REST function and force an exception to be thrown (changed the != to ==) the BadRequestAlertException exception as below:</p>
  
  <pre><code>if (userDTO.getId() == null) {
      throw new BadRequestAlertException("A new user cannot already have an 
          ID", "userManagement", "idexists");
  </code></pre>
  
  <p>I was expecting the error the show on the user-management-dialog.component.html as it has the declared tags:</p>
  
  <pre><code>&lt;jhi-alert-error&gt;&lt;/jhi-alert-error&gt;
  </code></pre>
  
  <p>But, all I got was the error in the server logs:</p>
  
  <pre><code>2018-02-06 15:49:17.025 ERROR 5352 --- [ XNIO-4 task-21] 
  c.s.hr.oa.web.rest.util.HeaderUtil       : Entity processing failed, A new 
  user cannot already have an ID
  
  2018-02-06 15:49:17.027  WARN 5352 --- [ XNIO-4 task-21] 
  o.z.p.spring.web.advice.AdviceTrait      : Bad Request: A new user cannot 
  already have an ID
  </code></pre>
  
  <p>I'm obviously missing something minor here? Would really appreciate any pointers.
  I was reading in other posts linked below and seems it should work. I've tried a few of the suggestions but they are based on older version of Angular and JHipster. I'm on Release 4.13.3</p>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/33202543/custom-error-message-for-bad-request-in-jhipster-project">Custom JHipster Error Messages</a></li>
  <li><a href="https://stackoverflow.com/questions/37727959/jhipster-jhi-alert-error-element-and-server-side-form-validation">Alert Errors</a></li>
  </ul>