title: NSOpenPanel malfunctioning
body: <p>I have an app that needs to have a &quot;choose file&quot; function and I used a button hooked up to a function using <code>NSOpenPanel</code> to do that. But after I tried to add a drag&amp;drop action, it won't work anymore. I reverted all my files to the version when the NSOpenPanel worked, but it's still the same. I also tried to restart my computer, all the same. Here's my function:</p>
  <pre><code>private func selectFile() {
      let openPanel = NSOpenPanel()
      openPanel.canChooseDirectories = false
      openPanel.allowsMultipleSelection = false
      openPanel.begin { response in
          if response == .OK {
              self.url = openPanel.url
          }
      }
  }
  </code></pre>
  <p>should I file a bug? should I reinstall Xcode?</p>