Typeless index call can fail against an index with a custom type.

mix_typeless_and_typed

PUT index
{
  "mappings": {
    "doc": {
       "properties": {
         "field": {"type": "keyword"}
       }
    }
  }
}


PUT index/_doc/1
{
  "other-field": "value"
}

> {
  "error": {
    "root_cause": [
      {
        "type": "mapper_parsing_exception",
        "reason": "Root mapping definition has unsupported parameters:  [doc : {properties={message={type=text, fields={keyword={type=keyword, ignore_above=256}}}}}]"
      }
    ],
    "type": "mapper_parsing_exception",
    "reason": "Root mapping definition has unsupported parameters:  [doc : {properties={message={type=text, fields={keyword={type=keyword, ignore_above=256}}}}}]"
  },
  "status": 400
}