Unable to obtain non-zero scores on results

[Cypre55]

I have used the docker one-liner to use the universal recommender. I have used the following config file.

{
    "engineId": "test",
       "engineFactory": "com.actionml.engines.ur.UREngine",
    "sparkConf": {
        "master": "local",
        "spark.serializer": "org.apache.spark.serializer.KryoSerializer",
        "spark.kryo.registrator": "org.apache.mahout.sparkbindings.io.MahoutKryoRegistrator",
        "spark.kryo.referenceTracking": "false",
        "spark.kryoserializer.buffer": "300m",
        "spark.executor.memory": "20g",
        "spark.driver.memory": "10g",
        "spark.es.index.auto.create": "true",
        "es.index.auto.create": "true",
        "spark.es.nodes": "elasticsearch",
        "spark.es.nodes.wan.only": "true"
    },
    "algorithm":{
        "indicators": [ 
            {
                "name": "read",
        "maxCorrelatorsPerItem": 5
            }
        ]
    }
}

After adding events 'read', two for two separate users. After training, running a simple query with an empty JSON returns all the names of the items but with their corresponding scores as 0.

I would like to know how to obtain non-zero scores for the results.