title: I cannot get the app to start. I get uncaughtype error util.isbrowser not a function
body: <p>I am using ionic 3 angular 5 to make an app. when i run the app i get <strong>uncaughtype error util.isbrowser not a function.</strong> My dependencies are angularfire2: 5.1.0, firebase: 5.7.2. please help me with this. I have googled alot but cannot find any solution to it. The error is from node_modules/@firebase/app. The error occur on the highlighted part.</p>
  
  <pre><code>var logger = new logger$1.Logger('@firebase/app');
  </code></pre>
  
  <p>// Firebase Lite detection
  if (<strong>util.isBrowser()</strong> &amp;&amp; 'firebase' in self) {
      logger.warn("\n    Warning: Firebase is already defined in the global scope. Please make sure\n    Firebase library is only loaded once.\n  ");
      var sdkVersion = self.firebase.SDK_VERSION;
      if (sdkVersion &amp;&amp; sdkVersion.indexOf('LITE') >= 0) {
          logger.warn("\n    Warning: You are trying to load Firebase while using Firebase Performance standalone script.\n    You should load Firebase Performance with this instance of Firebase to avoid loading duplicate code.\n    ");
      }
  }</p>