debug console showing "Tooltip is not defined"
<p>I'm using PrimeNG and Bootstrap 4 for an Angular2 app. Though the PrimeNG tooltip component works well, the debug console always shows this log:</p>

<pre><code>Uncaught ReferenceError: Tooltip is not defined
at Popover (eval at module.exports (addScript.js:9), &lt;anonymous&gt;:3524:32)
at eval (eval at module.exports (addScript.js:9), &lt;anonymous&gt;:3677:3)
at eval (&lt;anonymous&gt;)
at module.exports (addScript.js:9)
at Object.541 (bootstrap.js?41b4:1)
at __webpack_require__ (bootstrap a7ab881…:52)
at Object.1272 (scripts.bundle.js:8)
at __webpack_require__ (bootstrap a7ab881…:52)
at webpackJsonpCallback (bootstrap a7ab881…:23)
at scripts.bundle.js:1
</code></pre>

<p>I tried to comment out the PrimeNG part but the error still exists.
Has anyone met this before?</p>

<p>My angular-cli.json part:</p>

<pre><code>"styles": [
    "../node_modules/bootstrap/dist/css/bootstrap.css",
    "../node_modules/primeng/resources/primeng.min.css",
    "../node_modules/primeng/resources/themes/bootstrap/theme.css",
    "styles.css"
],
"scripts": [
  "../node_modules/jquery/dist/jquery.js",
  "../node_modules/tether/dist/js/tether.js",
  "../node_modules/bootstrap/dist/js/bootstrap.js"
],
</code></pre>

<p>And the only place I used tooltip is as follows</p>

<pre><code>import { TooltipModule } from 'primeng/primeng';

&lt;a class="list-item-lockup"
   routerLink="{{item.path}}"
   [pTooltip]="isSideBarCollapsed ? item.data.title : null"&gt;
  &lt;i class="fa {{item.data.icon}} fa-fw" aria-hidden="true"&gt;&lt;/i&gt;
  &lt;span [class.list-span-collapsed]="isSideBarCollapsed"&gt;{{item.data.title}}&lt;/span&gt;
&lt;/a&gt;
</code></pre>

<h2>UPDATE</h2>

<p>The problem comes from bootstrap.js`, after removing "../node_modules/bootstrap/dist/js/bootstrap.js", there should be no error.
Why would that be?</p>