Cisco module IOS error on parsing logs

  1. There are Cisco IOS logs on local machine and filebeat installed on it.
  2. Sending that logs to Elasticsearch (Without Logstash).
  3. When I discover those logs, error message appears and logs are not parsed:

> GoError: could not find delimiter: in remaining: ``, (offset: 15)

My Elastic Stack is 8.4.0
My Filebeat version is 8.4.0

What may be the problem?
Thank you.