title: Elasticsearch 1.2.1 exception: Root type mapping not empty after parsing
body: <p>After updating to Elasticsearch <code>1.2.1</code> I keep getting the following exception on the following mapping:</p>
  
  <pre><code>{
      "tags": {
          "properties": {
              "tags": {
                  "type": "string",
                  "index": "not_analyzed"
              }
          }
      }
  }
  </code></pre>
  
  <p>This is the exception:</p>
  
  <pre><code>Caused by: org.elasticsearch.index.mapper.MapperParsingException: Root type mapping not empty after parsing! Remaining fields: [tags : {properties={tags={index=not_analyzed, type=string}}}]
      at org.elasticsearch.index.mapper.DocumentMapperParser.parse(DocumentMapperParser.java:265)
      at org.elasticsearch.index.mapper.DocumentMapperParser.parseCompressed(DocumentMapperParser.java:189)
      at org.elasticsearch.index.mapper.MapperService.parse(MapperService.java:387)
      at org.elasticsearch.index.mapper.MapperService.merge(MapperService.java:253)
      at org.elasticsearch.cluster.metadata.MetaDataCreateIndexService$2.execute(MetaDataCreateIndexService.java:363)
  </code></pre>
  
  <p>Why is that?</p>