# Logstash generating exception in pipeline worker

**URL:** <https://discuss.elastic.co/t/logstash-generating-exception-in-pipeline-worker/104617>\
**Category:** Logstash\
**Created:** [October 19, 2017, 8:49pm UTC](https://discuss.elastic.co/t/logstash-generating-exception-in-pipeline-worker/104617 "2017-10-19T20:49:11Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![kenny123](https://avatars.discourse-cdn.com/v4/letter/k/7ab992/32.png) [@kenny123](https://discuss.elastic.co/u/kenny123)\
**Post date:** [October 19, 2017, 8:49pm UTC](https://discuss.elastic.co/t/logstash-generating-exception-in-pipeline-worker/104617/1 "2017-10-19T20:49:11Z")

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Hi ,  
when i run the logstash in the debug mode, it is generating error as the below.Can i please know whether the error is due to the wrong filter or not using of persistent queues.

```
Exception in pipelineworker, the pipeline stopped processing new events, please check your filterash. {"exception"=>"undefined method `to_hash' for []:Array", "backtrace"=>["(eval):126:in `filter_func'", "/root/logstash-aap/logstash-core/lib/logstash/pip "/root/logstash-aap/logstash-core/lib/logstash/pipeline.rb:379:in `worker_loop'", "/root/logstash-aap/logstash-core/lib/logstash/pipeline.rb:342:in `start_w
[FATAL] 2017-10-19 13:40:19.011 [LogStash::Runner] runner - An unexpected error occurred! {:error=>#<NoMethodError: undefined method `to_hash' for []:Array>,lter_func'", "/root/logstash-aap/logstash-core/lib/logstash/pipeline.rb:398:in `filter_batch'", "/root/logstash-aap/logstash-core/lib/logstash/pipeline.rb:37tash-aap/logstash-core/lib/logstash/pipeline.rb:342:in `start_workers'"]}
```

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<div class="post-metadata">

**Author:** ![magnusbaeck](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/magnusbaeck/32/44943_2.png) [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)\
**Post date:** [October 20, 2017, 4:44am UTC](https://discuss.elastic.co/t/logstash-generating-exception-in-pipeline-worker/104617/2 "2017-10-20T04:44:48Z")

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This is a bug in Logstash 5.6.3. Downgrade to 5.6.2 for now.

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<div class="post-metadata">

**Author:** ![kenny123](https://avatars.discourse-cdn.com/v4/letter/k/7ab992/32.png) [@kenny123](https://discuss.elastic.co/u/kenny123)\
**Post date:** [October 20, 2017, 6:40pm UTC](https://discuss.elastic.co/t/logstash-generating-exception-in-pipeline-worker/104617/3 "2017-10-20T18:40:09Z")

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Thank you..

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [November 17, 2017, 6:40pm UTC](https://discuss.elastic.co/t/logstash-generating-exception-in-pipeline-worker/104617/4 "2017-11-17T18:40:14Z")

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