title: Elasticsearch 7 : Root mapping definition has unsupported parameters (mapper_parsing_exception)
body: <p>When trying to insert the following mapping in Elasticsearch 7</p>
  
  <pre><code>PUT my_index/items/_mapping
  {
     "settings":{
  
     },
     "mappings":{
        "items":{
           "properties":{
              "products":{
                 "properties":{
                    "classification":{
                       "type":"text",
                       "fields":{
                          "raw":{
                             "type":"keyword",
                             "ignore_above":256
                          }
                       }
                    },
                    "original_text":{
                       "type":"text",
                       "store":false,
                       "fields":{
                          "raw":{
                             "type":"keyword",
                             "ignore_above":256
                          }
                       }
                    }
                 }
              },
              "title":{
                 "type":"text",
                 "fields":{
                    "raw":{
                       "type":"keyword",
                       "ignore_above":256
                    }
                 },
                 "analyzer":"autocomplete"
              },
              "image":{
                 "properties":{
                    "type":{
                       "type":"text",
                       "fields":{
                          "raw":{
                             "type":"keyword",
                             "ignore_above":256
                          }
                       }
                    },
                    "location":{
                       "type":"text",
                       "store":false,
                       "fields":{
                          "raw":{
                             "type":"keyword",
                             "ignore_above":256
                          }
                       }
                    }
                 }
              }
           }
        }
     }
  }
  </code></pre>
  
  <p>I get an error of the form:</p>
  
  <pre><code>{
  "error": {
      "root_cause": [
      {
          "type": "mapper_parsing_exception",
          "reason": "Root mapping definition has unsupported parameters:  
  </code></pre>
  
  <p>What is causing this error?</p>