I have 2 ViewController, let's say Feed and Login. Initial page is the Feed and if not authenticated, user is getting directed to Login page. After filling the form, on successful login, I am trying to unwind back to Feed page.
In FeedVC, I added:
@IBAction func unwindToFeed(segue: UIStoryboardSegue){
}
In LoginVC, on login-button press
@IBAction func loginButton(sender: AnyObject) {
  func authenticatedUser (...) {
    if error != nil {
          // error handling
    } else {
         // success
        NSOperationQueue.mainQueue().addOperationWithBlock({
           self.performSegueWithIdentifier("unwindToFeed", sender: self)
        })
    }
  } 
}
However, on success, it doesn't get unwind-ed, and I'm getting an error
Terminating app due to uncaught exception 'NSInvalidArgumentException', > reason: 'Receiver ( 0x7fd789a2cab0>) has no segue with identifier 'unwindToFeed''
In Storyboard, in LoginVC, I also tried to ctrl+dragging from Yellow (ViewController) to Exit, at the top. However as soon as I do that, I receive "Segues initiated directly from view controllers must have an identifier" and in Login View Controller Scene it shows Unwind segue to 'Exit'.
What am I doing wrong?
 
    