Getting Error decoding JSON: invalid character

Elastic Stack
1

I have tried Filebeat 7.7.0 and 7.7.1, setup with the following filebeat.yml
filebeat.inputs:

  • type: container
    paths:
    • '/var/lib/docker/containers//.log'
      json.keys_under_root: true
      json.add_error_key: true
      json.message_key: log
      json.overwrite_keys: true

processors:

  • add_docker_metadata: ~

  • decode_json_fields:
    fields: {"log"}
    target: "json"

output.elasticsearch:
hosts: ["elasticsearch:9200"]
indices:
- index: "filebeat-%{[agent.version]}-%{+yyyy.MM.dd}"

logging.json: true
logging.metrics.enabled: false

getting this error
Error decoding JSON: invalid character

Any help on the same