Fatal error: Uncaught Elasticsearch\Common\Exceptions\BadRequest400Exception: {"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"field name is null or empty"}],"type":"illegal_argument_exception","reason":"field name is null or empty"},"status":400} in /var/www/vhosts/k41k.de/httpdocs/vendor/elasticsearch/elasticsearch/src/Elasticsearch/Connections/Connection.php:620 Stack trace: #0 /var/www/vhosts/k41k.de/httpdocs/vendor/elasticsearch/elasticsearch/src/Elasticsearch/Connections/Connection.php(279): Elasticsearch\Connections\Connection->process4xxError(Array, Array, Array) #1 /var/www/vhosts/k41k.de/httpdocs/vendor/react/promise/src/FulfilledPromise.php(25): Elasticsearch\Connections\Connection->Elasticsearch\Connections\{closure}(Array) #2 /var/www/vhosts/k41k.de/httpdocs/vendor/guzzlehttp/ringphp/src/Future/CompletedFutureValue.php(55): React\Promise\FulfilledPromise->then(Object(Closure), NULL, NULL) #3 /var/www/vhosts/k41k.de/httpdocs/vendor/guzzlehttp/ringphp/src/Core.php(341): GuzzleHttp\Ring\Fut in /var/www/vhosts/k41k.de/httpdocs/vendor/elasticsearch/elasticsearch/src/Elasticsearch/Connections/Connection.php on line 620