Elasticsearch : Root mapping definition has unsupported parameters index : not_analyzed

You're almost here, you're just missing a few things:

PUT /test
{
  "mappings": {
    "type_name": {                <--- add the type name
      "properties": {             <--- enclose all field definitions in "properties"
        "field1": {
          "type": "integer"
        },
        "field2": {
          "type": "integer"
        },
        "field3": {
          "type": "string",
          "index": "not_analyzed"
        },
        "field4,": {
          "type": "string",
          "analyzer": "autocomplete",
          "search_analyzer": "standard"
        }
      }
    }
  },
  "settings": {
     ...
  }
}

UPDATE

If your index already exists, you can also modify your mappings like this:

PUT test/_mapping/type_name
{
    "properties": {             <--- enclose all field definitions in "properties"
        "field1": {
          "type": "integer"
        },
        "field2": {
          "type": "integer"
        },
        "field3": {
          "type": "string",
          "index": "not_analyzed"
        },
        "field4,": {
          "type": "string",
          "analyzer": "autocomplete",
          "search_analyzer": "standard"
        }
    }
}

UPDATE:

As of ES 7, mapping types have been removed. You can read more details here

I hope the above answer works for elastic search <7.0 but in 7.0 we cannot specify doc type and it is no longer supported. And in that case if we specify doc type we get similar error.

I you are making use of Elastic search 7.0 and Nest C# lastest version(6.6). There are some breaking changes with ES 7.0 which is causing this issue. This is because we cannot specify doc type and in the version 6.6 of NEST they are using doctype. So in order to solve that untill NEST 7.0 is released, we need to download their beta package

Please go through this link for fixing it

https://xyzcoder.github.io/elasticsearch/nest/2019/04/12/es-70-and-nest-mapping-error.html

EDIT: NEST 7.0 is now released. NEST 7.0 works with Elastic 7.0. See the release notes here for details.

Check your Elastic version.

I had these problem because I was looking at the incorrect version's documentation.