Completion Suggesters stopped working with 2.2.0 upgrade

Hi there,

We've hit an error where a completion suggester which was working before is no longer working. The error thrown is the following:

{"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"Can't write raw bytes whose xcontent-type can't be guessed"}],"type":"illegal_argument_exception","reason":"Can't write raw bytes whose xcontent-type can't be guessed"},"status":400}

Mapping for suggest-category is as follows:

suggest-category: {
    type: "completion",
    analyzer: "simple",
    payloads: true,
    preserve_separators: true,
    preserve_position_increments: true,
    max_input_length: 50

Query is as follows:

    index: "advertisers-current",
    search_type: "count",
    body: {
        suggest: {
            text: "estate",
            suggest-category: {
                completion: {
                    field: "suggest-category",
                    fuzzy: {
                        fuzziness: 0

The suggest-category field is an array of values.
Any ahem suggestions? The error is pretty cryptic. This works flawlessly on 2.1.1.

Hi datashaman,

What type are your payloads?

I'm not sure if you're still having this issue, but in my case I saw this error because I was using String payloads. Checking the docs revealed that payloads are "arbitrary JSON objects", so I guess the fact that this worked pre-2.2.0 was a bug.

Changing the payload to a single-property JSON object resolved the error.

Thanks very much for your help, that solved my problem!