无法将类型'（）-> Void'的值分配给'（（）-> Void）！'

由于我使用Swift 3，因此出现以下错误。

无法将类型'（（LLSimpleCamera ?, NSError？）-> Void'的值分配为类型'（（（LLSimpleCamera ?, Error？）-> Void）！'

有谁知道该怎么办？这是我的代码。

camera.onError = { (camera: LLSimpleCamera?, error: NSError?) -> Void in
        print("Camera error: \(error)")

        if error.domain == LLSimpleCameraErrorDomain {
            if error.code == Int(LLSimpleCameraErrorCodeCameraPermission.rawValue) || error.code == Int(LLSimpleCameraErrorCodeMicrophonePermission.rawValue) {

                let alertVC = UIAlertController(title: "Ooops!", message: "We need permission for the camera. Please go to your settings.", preferredStyle: .alert)
                let okAction = UIAlertAction(title: "OK", style: .default, handler: nil)
                let settingsAction = UIAlertAction(title: "Settings", style: .default) { (action) in
                    UIApplication.shared.openURL(URL(string: UIApplicationOpenSettingsURLString)!)
                }

                alertVC.addAction(okAction)
                alertVC.addAction(settingsAction)

                self.present(alertVC, animated: true, completion: nil)
            }
        }
    }