Failed to connect (storyboard) outlet from (NSApplication) to (NSNibExternalObjectPlaceholder) error in Cocoa and storyboard

Question

I\'ve tried to build a sample Cocoa app on which I want to connect UI components put on storyboard to ViewController.swift as either an IBOutlet or

Answer 1

Failed to connect (storyboard) outlet from (NSApplication) to (NSNibExternalObjectPlaceholder): missing setter or instance variable

The IBAction methods working like it should, see Apple Dev Forums:

"This is a known issue ... The messages are harmless and do not indicate a problem with your code."

Apple Dev Forums: OS X Storyboard failure

Thats not why your code is not working, you need to fix the following:

A) Here is my working code to set the title - using self.view.window.title instead self.title:

@IBAction func btnSetWindowTitle(sender : AnyObject) {
    if self.txtTitle.stringValue != "" {
        println(self.view.window.title)
        println(self.txtTitle.stringValue)
        self.view.window.title = self.txtTitle.stringValue
    }
}

B) In Interface Builder you need to set NSBox "Box Type" to "Custom":

And that's it: