title: Unwanted red lines when the unwind segue is performed
body: <p>I have a view controller, embedded in a navigation controller, which has a button and connects me with <strong>another</strong> view controller with a button. I have ctrl dragged from the button of the <strong>second</strong> view controller to the exit in the Storyboard creating an <strong><em>unwind segue</em></strong>. While the <strong><em>unwind segue</em></strong> works as wanted (When I click the button it <strong>removes</strong> the current view controller and gets me to the <strong>first</strong> view controller) but once that happens my current view has some <em>red lines</em> for no apparent reason. Why does this happen? Has to do with my Xcode installation or does it have to do with Xcode in general?<a href="https://i.stack.imgur.com/aDvZ2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aDvZ2.png" alt="red lines in my view"></a></p>
  
  <p>I have Xcode 10.1 and although there is nothing fancy in my code here it is anyway: </p>
  
  <pre><code>import UIKit
  
  class PresentedViewController: UIViewController {
      @IBAction func myUnwindAction(unwindSegue: UIStoryboardSegue)
      {
          print("You learned to use unwindSegue")
      }
  }
  </code></pre>