title: Ionic 3/4, ERROR TypeError: _co.toBoarding is not a function
body: <p>I get an error using Ionic 3/4, I get error to navigate between 2 component, I don't know why, 3 months ago was fine using Ionic, but today I get an error. I use lazyload to navigate 2 component.</p>
  
  <p>This is error that I get :</p>
  
  <pre><code>ERROR TypeError: _co.toBoarding is not a function
      at Object.eval [as handleEvent] (HomePage.html:12)
      at handleEvent (core.js:13589)
      at callWithDebugContext (core.js:15098)
      at Object.debugHandleEvent [as handleEvent] (core.js:14685)
      at dispatchEvent (core.js:10004)
      at core.js:10629
      at HTMLButtonElement.&lt;anonymous&gt; (platform-browser.js:2628)
      at t.invokeTask (polyfills.js:3)
      at Object.onInvokeTask (core.js:4751)
      at t.invokeTask (polyfills.js:3)
  </code></pre>
  
  <p>and this is my full script :</p>
  
  <p>home.html</p>
  
  <pre><code>&lt;ion-header&gt;
    &lt;ion-navbar&gt;
      &lt;ion-title&gt;
        Ionic Blank
      &lt;/ion-title&gt;
    &lt;/ion-navbar&gt;
  &lt;/ion-header&gt;
  
  &lt;ion-content padding&gt;
    The world is your oyster.
    &lt;p&gt;
      &lt;button ion-button (click)="toBoarding()"&gt;Button&lt;/button&gt;
    &lt;/p&gt;
  &lt;/ion-content&gt;
  </code></pre>
  
  <p>home.ts</p>
  
  <pre><code>import { Component } from '@angular/core';
  import { NavController } from 'ionic-angular';
  
  @Component({
    selector: 'page-home',
    templateUrl: 'home.html'
  })
  export class HomePage {
  
    constructor(public navCtrl: NavController) {
  
    }
  
    toBoarding() {
      this.navCtrl.push('BoardingPage');
    }
  }
  </code></pre>
  
  <p>boarding.html</p>
  
  <pre><code>&lt;ion-header&gt;
  
    &lt;ion-navbar&gt;
      &lt;ion-title&gt;boarding&lt;/ion-title&gt;
    &lt;/ion-navbar&gt;
  
  &lt;/ion-header&gt;
  
  
  &lt;ion-content padding&gt;
  
  &lt;/ion-content&gt;
  </code></pre>
  
  <p>boarding.ts</p>
  
  <pre><code>import { Component } from '@angular/core';
  import { IonicPage, NavController, NavParams } from 'ionic-angular';
  
  @IonicPage()
  @Component({
    selector: 'page-boarding',
    templateUrl: 'boarding.html',
  })
  export class BoardingPage {
  
    constructor(public navCtrl: NavController, public navParams: NavParams) {
    }
  
    ionViewDidLoad() {
      console.log('ionViewDidLoad BoardingPage');
    }
  
  }
  </code></pre>
  
  <p>So, What should I do to solve this problem, or you have solving to solve this problem, please help me.</p>
  
  <p>Thanks.</p>