title: 'The default Firebase app has not yet been configured' error
body: <p>I'm getting this error in my iOS app with Firebase integrated:</p>
  
  <pre><code>&lt;Error&gt; [Firebase/Core][I-COR000003] The default Firebase app has not yet been configured. Add [FIRApp configure] to your application initialization
  </code></pre>
  
  <p>However I've already added <code>[FIRApp configure]</code> in AppDelegate:</p>
  
  <pre><code>- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
      // Override point for customization after application launch.
  
      [FIRApp configure];
   }
  </code></pre>
  
  <p>How do I fix this? I'm also using Firebase Authentication, Database, and Messaging all with Pods.</p>