6.3.2配置script function报错

想在function_score里面使用script_score，
 
 
请求是：

  curl  -H "Content-Type: application/json" -XGET 'localhost:9200/test_index/metaDoc/_search?pretty' -d '

  {

    "explain": true,

    "query": {

      "function_score": {

          "query": { 

            "bool": {

              "must": [ {

                "match_phrase": {

                    "docName": "活动"

                  }

                }

              ]

            }

          },

          "functions": [

            {

              "field_value_factor": {

                "field":    "clicks",

                "modifier": "log1p",

                "factor":   2,

                "missing": 0

              }

            },

            {

              "script_score" : {

                "script" : {

                    "params": {

                        "a": 4,

                        "b": 1

                    },

                    "inline": "params.a / doc['clicks'].value"

                }

            }

          }

        ],

        "boost_mode": "sum",

        "score_mode": "sum"

      }

    },

    "size": 4

  }'

报错是：
 

{

  "error" : {

    "root_cause" : [

      {

        "type" : "script_exception",

        "reason" : "compile error",

        "script_stack" : [

          "params.a / doc[clicks].value",

          "               ^---- HERE"

        ],

        "script" : "params.a / doc[clicks].value",

        "lang" : "painless"

      }

    ],

    "type" : "search_phase_execution_exception",

    "reason" : "all shards failed",

    "phase" : "query",

    "grouped" : true,

    "failed_shards" : [

      {

        "shard" : 0,

        "index" : "test_index",

        "node" : "gDlILShpRcaaiuzMO75Jcw",

        "reason" : {

          "type" : "query_shard_exception",

          "reason" : "script_score: the script could not be loaded",

          "index_uuid" : "0nqvfTFlSPmm5rZXV_R6mQ",

          "index" : "test_index",

          "caused_by" : {

            "type" : "script_exception",

            "reason" : "compile error",

            "script_stack" : [

              "params.a / doc[clicks].value",

              "               ^---- HERE"

            ],

            "script" : "params.a / doc[clicks].value",

            "lang" : "painless",

            "caused_by" : {

              "type" : "illegal_argument_exception",

              "reason" : "Variable [clicks] is not defined."

            }

          }

        }

      }

    ],

    "caused_by" : {

      "type" : "script_exception",

      "reason" : "compile error",

      "script_stack" : [

        "params.a / doc[clicks].value",

        "               ^---- HERE"

      ],

      "script" : "params.a / doc[clicks].value",

      "lang" : "painless",

      "caused_by" : {

        "type" : "illegal_argument_exception",

        "reason" : "Variable [clicks] is not defined."

      }

    }

  },

  "status" : 400

}

 
 
然后不知道是不是配置的问题，在elasticsearch.yml里面加上了：

script.stored: true

script.inline: true

script.search: true

script.engine.groovy.stored.aggs: true

script.engine.groovy.inline.search: true

 但是重启会报错，

[WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler]  uncaught exception in thread [main]

org.elasticsearch.bootstrap.StartupException: java.lang.IllegalArgumentException: unknown setting [script.engine.groovy.stored.aggs] please check that any required plugins are installed, or check the breaking changes documentation for removed settings

	at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:140) ~[elasticsearch-6.3.2.jar:6.3.2]

	at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:127) ~[elasticsearch-6.3.2.jar:6.3.2]

	at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-6.3.2.jar:6.3.2]

	at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) ~[elasticsearch-cli-6.3.2.jar:6.3.2]

	at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-6.3.2.jar:6.3.2]

大概长这样，是不是现在不支持了？
请问要如何正确使用script呢？