从片段登录Facebook期间，我的应用程序消失了

Question

从片段登录Facebook期间，我的应用程序消失了。可能是什么问题呢？谁能帮我这个忙。

Facebook登录方法

        private void facebooklogin() {
        FacebookSdk.sdkInitialize(getApplicationContext());
        AppEventsLogger.activateApp(getApplicationContext());
        callbackManager = CallbackManager.Factory.create();
        LoginButton loginButton = (LoginButton) getActivity().findViewById(R.id.login_button);
        loginButton.setReadPermissions(Arrays.asList(EMAIL));
        loginButton.setFragment(this);

        loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {

            }

            @Override
            public void onCancel() {

            }

           @Override
            public void onError(FacebookException exception) {
            }
        });
    }


   @Override
   public void onActivityResult(int requestCode, int resultCode, Intent data) {
       callbackManager.onActivityResult(requestCode, resultCode, data);
   }