title: Custom Font not working in Swift/Xcode
body: <p>I have a problem with a custom font in my project. I tried both ways: by code and interface builder. </p>
  
  <p>I added TeamSpiritNF.ttf to the project and added it to the info.plist (Fonts provided by application). </p>
  
  <p>Then in the code I entered this:</p>
  
  <pre><code>self.navigationController?.navigationBar.titleTextAttributes = [ NSFontAttributeName: UIFont(name: "TeamSpiritNF", size: 30)!]
  </code></pre>
  
  <p>When entering the screen in the simulator the App crashes: </p>
  
  <pre><code>fatal error: unexpectedly found nil while unwrapping an Optional value
  </code></pre>
  
  <p>But the same line works fine if I change the font name to Helvetica for example.</p>
  
  <p>And if I use this font for a label in the interface builder (where I can select it from the dropdown), it is shown correct in the preview. But when I run the application in the simulator entering that screen is delayed and the label uses Helvetica Neue instead of TeamSpiritNF.</p>
  
  <p>Anyone has an idea what the problem could be?</p>