Vfrdtyky

I am using the Siri speech kit and while using it and clicking of the button some times it will be terminated and shows the error message as title.
I am using the single button and when first clicks it here to our voice and and again click on the button stop listening that is the main functionality.

`func startRecording() {

        messageField.text = ""

        if recognitionTask != nil {

            recognitionTask?.cancel()

            recognitionTask = nil

        }

        let audioSession = AVAudioSession.sharedInstance()

        do {

            try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord,mode: AVAudioSessionModeDefault, options: .defaultToSpeaker)

            try audioSession.setMode(AVAudioSessionModeMeasurement)

            try audioSession.setActive(true, with: .notifyOthersOnDeactivation)

        } catch {

            print("audioSession properties weren't set because of an error.")

        }

        recognitionRequest = SFSpeechAudioBufferRecognitionRequest()

        let inputNode = audioEngine.inputNode

        guard let recognitionRequest = recognitionRequest else {

            fatalError("Unable to create an SFSpeechAudioBufferRecognitionRequest object")

        }

        recognitionRequest.shouldReportPartialResults = true

        recognitionTask = speechRecognizer.recognitionTask(with: recognitionRequest, resultHandler: { (result, error) in

            var isFinal = false

            if result != nil {

                self.messageField.text = result?.bestTranscription.formattedString

                //   self.textViewShouldEndEditing(self.messageField)

                isFinal = (result?.isFinal)!

            }

            if error != nil || isFinal {

                self.audioEngine.stop()

                self.audioEngine.inputNode.removeTap(onBus: 0)



                self.recognitionRequest = nil

                self.recognitionTask = nil

                // self.microphoneButton.isEnabled = true

            }

        })

        let recordingFormat = inputNode.outputFormat(forBus: 0)

        inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { (buffer, when) in

            self.recognitionRequest?.append(buffer)

        }

        audioEngine.prepare()



        do {

            try audioEngine.start()

        } catch {

            print("audioEngine couldn't start because of an error.")

        }

        messageField.text = "Say something, I'm listening!"

    }`

`

please help me out,
Thanks.