title: Ionic Runtime Error Uncaught (in promise): navigation stack needs at least one root page
body: <p>I am creating ionic 3 app with WordPress backend. Here is my code</p>
  
  <pre><code>import { Component } from '@angular/core';
  import { NavController, NavParams, LoadingController } from "ionic-angular";
  import { ViewController } from 'ionic-angular';
  
  
  import { WordpressProvider } from './../../providers/wordpress/wordpress'; 
  import { PostPage } from './../../pages/post/post';
  
  @Component({
    selector: 'page-blog',
    templateUrl: 'blog.html',
  })
  export class BlogPage {
  
    posts: any = [];
    private loading: any;
  
    constructor(
      public navCtrl: NavController, 
      public navParams: NavParams,
      public wordpress: WordpressProvider,
      public loadingCtrl: LoadingController,  
      public viewCtrl: ViewController,
    ) { 
      this.loading = this.loadingCtrl.create();
      this.loading.present();
    }
  
    ionViewDidLoad() {
      console.log('ionViewDidLoad BlogPage'); 
      this.wordpress.retrievePosts().subscribe(results =&gt; {
        this.posts = results;
        this.loading.dismiss();  
      });
    } 
  
    openPostPage(post) {
      this.navCtrl.push(PostPage, {"post": post});
    }
  
  }
  </code></pre>
  
  <p>Now i call in header </p>
  
  <pre><code>&lt;ion-header&gt;
      &lt;ion-toolbar color="white_bg"&gt;  
        &lt;ion-buttons left&gt;
          &lt;button ion-button (click)="viewCtrl.dismiss()"&gt;
            &lt;ion-icon name="arrow-back"&gt;&lt;/ion-icon&gt;
          &lt;/button&gt;
        &lt;/ion-buttons&gt;
        &lt;ion-title center toolbar-title&gt;&lt;img src="./assets/images/logo.png" class="logo"/&gt;&lt;/ion-title&gt;   
        &lt;ion-buttons end&gt;
            &lt;button ion-button menuToggle&gt;
              &lt;ion-icon name="menu"&gt;&lt;/ion-icon&gt;
            &lt;/button&gt; 
        &lt;/ion-buttons&gt; 
      &lt;/ion-toolbar&gt;
    &lt;/ion-header&gt;
  </code></pre>
  
  <p>this give me this error </p>
  
  <p><strong>Runtime Error</strong>
  Uncaught (in promise): navigation stack needs at least one root page</p>
  
  <p>Can anyone point what is going wrong?</p>