Ruby exception occurred: undefined method `[]' for nil:NilClas

[MikaelLindstrom]

Hi all,
We're seeing these two messages in the logs:

/var/log/logstash/logstash-plain.log:
[2018-08-09T05:13:41,528][ERROR][logstash.filters.ruby ] Ruby exception occurred: undefined method `[]' for nil:NilClass

When we add stdout {
codec => rubydebug
}
to logstash output, we also see this error in the /var/log/messages:
Aug 9 05:13:41 labelk kibana: {"type":"log","@timestamp":"2018-08-09T12:13:41Z","tags":["plugin","debug"],"pid":20218,"message":"Checking Elasticsearch version"}

which points to the kibana checking the elasticversion triggering this ruby exception.

Has anyone seen this and found a fix?

Regards,
Mike

[Badger]

It's unrelated to Kibana. In your logstash configuration you have a ruby filter, and it is trying to index into a variable that is nil. What does your ruby filter look like?