Apache Druid

Hello all,
I need help with Kafka Lookup, where the topic is in Avro.
I get the following error:
```WARN  category: org.apache.druid.query.lookup.LookupUtils - message: Lookup [my_lookup] could not be serialized properly. Please check its configuration. Error: Cannot construct instance of `org.apache.druid.query.lookup.KafkaLookupExtractorFactory`, problem: Guice configuration errors:

1) No implementation for org.apache.druid.server.lookup.namespace.cache.NamespaceExtractionCacheManager was bound.
  while locating org.apache.druid.server.lookup.namespace.cache.NamespaceExtractionCacheManager

1 error
 at [Source: (byte[])":)```
Any help?

Here is my setting:
```{
  "type": "kafka",
  "kafkaProperties": {
    "bootstrap.servers": "kafka-bootstrap:9092"
  },
  "kafkaTopic": "myTopic"
}```
I know I need to specify a schema somewhere, I just can't find where.