title: Angular 6 ng build --prod error "ERROR Error: ngIfElse must be a TemplateRef, but received 'true'."
body: <p>ERROR Error: ngIfElse must be a TemplateRef, but received 'true'</p>
  <p>HTML File</p>
  <pre class="lang-html prettyprint-override"><code>&lt;select class=&quot;form-control&quot;&gt;
    &lt;option selected value=&quot;0&quot;&gt;Select Manufacturer&lt;/option&gt;
    &lt;option *ngFor=&quot;let brand of allMakes&quot;&gt;
       {{ brand.brand }}
    &lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  <p>ts file</p>
  <pre class="lang-js prettyprint-override"><code>this.allMakes = [{
    id: '1',
    brand: 'Mazda'
  },
  {
    id: '2',
    brand: 'Audi',
  }];
  </code></pre>
  <p>It all started right after i upgraded from Angular 5 to Angular 6</p>
  <p>Console Log Error</p>
  <pre><code>ERROR Error: ngIfElse must be a TemplateRef, but received 'true'.
    at Vt (main.6e360f04b7d39ee1dc33.bundle.js:1)
    at t.set [as ngIfElse] (main.6e360f04b7d39ee1dc33.bundle.js:1)
    at Sa (main.6e360f04b7d39ee1dc33.bundle.js:1)
    at main.6e360f04b7d39ee1dc33.bundle.js:1
    at main.6e360f04b7d39ee1dc33.bundle.js:1
    at es (main.6e360f04b7d39ee1dc33.bundle.js:1)
    at Os (main.6e360f04b7d39ee1dc33.bundle.js:1)
    at Object.updateDirectives 
    (main.6e360f04b7d39ee1dc33.bundle.js:1)
    at Object.updateDirectives (main.6e360f04b7d39ee1dc33.bundle.js:1)
    at ts (main.6e360f04b7d39ee1dc33.bundle.js:1)
  </code></pre>