An error that I see coming up frequently in the Kafka Connect community (e.g. mailing list, Slack group, StackOverflow) is:

JsonDeserializer with schemas.enable requires "schema" and "payload" fields and may not contain additional fields

or

No fields found using key and value schemas for table: foo-bar

You can see an explanation, and solution, for the issue in my StackOverflow answer here: https://stackoverflow.com/a/45940013/350613

If you’re using schemas.enable in the Connector configuration, you must have schema and payload as the root-level elements of your JSON message ( Which is pretty much verbatim what the error says 😁), like this:

{
    "schema": {
        "type": "struct",
        "fields": [{
            "type": "int32",
            "optional": true,
            "field": "c1"
        }, {
            "type": "string",
            "optional": true,
            "field": "c2"
        }, {
            "type": "int64",
            "optional": false,
            "name": "org.apache.kafka.connect.data.Timestamp",
            "version": 1,
            "field": "create_ts"
        }, {
            "type": "int64",
            "optional": false,
            "name": "org.apache.kafka.connect.data.Timestamp",
            "version": 1,
            "field": "update_ts"
        }],
        "optional": false,
        "name": "foobar"
    },
    "payload": {
        "c1": 10000,
        "c2": "bar",
        "create_ts": 1501834166000,
        "update_ts": 1501834166000
    }
}

So either make sure your JSON message adheres to this format, or tell the JSON Converter not to try and fetch a schema, by setting the following in the Connector config:

"value.converter.schemas.enable": "false"