Alexa AudioPlayer.PlaybackNearlyFinished无效响应

Question

我想通过循环音频来开发alexa技能。

我正确接收到请求消息AudioPlayer.PlaybackNearlyFinished，并使用json响应进行了响应：

{
              "version": "1.0",
              "response": {
              "outputSpeech": {},
              "shouldEndSession": true,
                "directives": [
                  {
                    "type": "AudioPlayer.Play",
                    "playBehavior": "ENQUEUE",
                    "audioItem": {
                      "stream": {
                        "token": "token_new", 
                        "expectedPreviousToken": "old_token",
                        "url": "MP3URL",
                        "offsetInMilliseconds": 52
                      }
                    }
                  }
                ]
              }
            }

但是alexa响应错误：

"request":{"type":"System.ExceptionEncountered","requestId":"amzn1.echo-api.request.REQUESTID","timestamp":"2019-06-16T16:17:25Z","locale":"it-IT","error":{"type":"INVALID_RESPONSE","message":"An exception occurred while dispatching the request to the skill."},"cause":{"requestId":"amzn1.echo-api.request.REQUESTID"}}}

怎么了？我认为请求还可以

非常感谢