我正在通过BitSensor将Kibana插件与Elastalert服务器一起使用 我遵循文档指南中的所有步骤，但是启动Elastalert服务器时出现错误
dat@dat-VirtualBox:~/Downloads/kibana-oss-6.4.2-linux-x86_64/elastalert$ npm start
> @bitsensor/elastalert@1.0.0 start /home/dat/Downloads/kibana-oss-6.4.2-linux-x86_64/elastalert
> sh ./scripts/start.sh
08:56:09.102Z INFO elastalert-server: Config: No config.dev.json file was found in /home/dat/Downloads/kibana-oss-6.4.2-linux-x86_64/elastalert/config/config.dev.json.
08:56:09.108Z INFO elastalert-server: Config: Proceeding to look for normal config file.
08:56:09.108Z INFO elastalert-server: Config: A config file was found in /home/dat/Downloads/kibana-oss-6.4.2-linux-x86_64/elastalert/config/config.json. Using that config.
08:56:09.115Z INFO elastalert-server: Router: Listening for GET request on /.
08:56:09.116Z INFO elastalert-server: Router: Listening for GET request on /status.
08:56:09.116Z INFO elastalert-server: Router: Listening for GET request on /status/control/:action.
08:56:09.116Z INFO elastalert-server: Router: Listening for GET request on /status/errors.
08:56:09.116Z INFO elastalert-server: Router: Listening for GET request on /rules.
08:56:09.119Z INFO elastalert-server: Router: Listening for GET request on /rules/:id.
08:56:09.119Z INFO elastalert-server: Router: Listening for POST request on /rules/:id.
08:56:09.119Z INFO elastalert-server: Router: Listening for DELETE request on /rules/:id.
08:56:09.120Z INFO elastalert-server: Router: Listening for GET request on /templates.
08:56:09.120Z INFO elastalert-server: Router: Listening for GET request on /templates/:id.
08:56:09.120Z INFO elastalert-server: Router: Listening for POST request on /templates/:id.
08:56:09.121Z INFO elastalert-server: Router: Listening for DELETE request on /templates/:id.
08:56:09.121Z INFO elastalert-server: Router: Listening for POST request on /test.
08:56:09.121Z INFO elastalert-server: Router: Listening for GET request on /config.
08:56:09.121Z INFO elastalert-server: Router: Listening for POST request on /config.
08:56:09.121Z INFO elastalert-server: Router: Listening for POST request on /download.
08:56:09.121Z INFO elastalert-server: Router: Listening for GET request on /metadata/:type.
08:56:09.122Z INFO elastalert-server: Router: Listening for GET request on /mapping/:index.
08:56:09.131Z INFO elastalert-server: ProcessController: Starting ElastAlert
08:56:09.131Z INFO elastalert-server: ProcessController: Creating index
08:56:09.163Z ERROR elastalert-server:
Server: Starting server failed with error: TypeError: Cannot read property 'toString' of null
at ProcessController.start (/home/dat/Downloads/kibana-oss-6.4.2-linux-x86_64/elastalert/src/controllers/process/index.js:46:28)
at /home/dat/Downloads/kibana-oss-6.4.2-linux-x86_64/elastalert/src/elastalert_server.js:71:33
at /home/dat/Downloads/kibana-oss-6.4.2-linux-x86_64/elastalert/src/common/config/server_config.js:60:9
at Array.forEach (<anonymous>)
at /home/dat/Downloads/kibana-oss-6.4.2-linux-x86_64/elastalert/src/common/config/server_config.js:59:22
at <anonymous>
08:56:09.165Z INFO elastalert-server: Server: Stopping server
08:56:09.166Z INFO elastalert-server: ProcessController: ElastAlert is not running
08:56:09.167Z INFO elastalert-server: Server: Server stopped. Bye!
当我检查index.js：46：28时。我认为创建索引有问题，但我不知道如何解决它。有人有解决的想法 这是我的index.js文件
// Create ElastAlert index if it doesn't exist yet
logger.info('Creating index');
var indexCreate = spawnSync('python', ['-m', 'elastalert.create_index', '--index', 'elastalert_status', '--old-index', ''], {
cwd: this._elastalertPath
});
// Redirect stdin/stderr to logger
if (indexCreate.stdout.toString() !== '') { ###### error in here
logger.info(indexCreate.stdout.toString());
}
if (indexCreate.stderr.toString() !== '') {
logger.error(indexCreate.stderr.toString());
}