崩溃使用解析用户名/电子邮件登录与Facebook登录线程1信号sigabrt

Question

override func viewDidAppear(animated: Bool) {

    if PFUser.currentUser() != nil {

        self.performSegueWithIdentifier("loggedin", sender: self)

    }

    if (FBSDKAccessToken.currentAccessToken() != nil) {

        // User is already logged in, do work such as go to next view controller.

        self.performSegueWithIdentifier("loggedin", sender: self)

    } else  {

        let loginView : FBSDKLoginButton = FBSDKLoginButton()
        self.view.addSubview(loginView)
        loginView.center = self.view.center
        loginView.readPermissions = ["public_profile", "email", "user_friends"]
        loginView.delegate = self

    }

}

AppDelegate中的错误消息错误说明：线程1：信号SIGABRT。我已从初始登录页面重新输入我的连接到标签栏导航器，我仍然遇到此问题。 Appdelegate中的错误消息：

<i>@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate Thread 1: signal  SIGABRT<i>