# Logstash error "exception in filterworker"

**URL:** <https://discuss.elastic.co/t/logstash-error-exception-in-filterworker/26406>\
**Category:** Logstash\
**Created:** [July 28, 2015, 9:47am UTC](https://discuss.elastic.co/t/logstash-error-exception-in-filterworker/26406 "2015-07-28T09:47:13Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![nguafogu78](https://avatars.discourse-cdn.com/v4/letter/n/43a26b/32.png) [@nguafogu78](https://discuss.elastic.co/u/nguafogu78)\
**Post date:** [July 28, 2015, 9:47am UTC](https://discuss.elastic.co/t/logstash-error-exception-in-filterworker/26406/1 "2015-07-28T09:47:13Z")

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Hi,

Does someone encountered the following error before:

Jul 28 08:56:32 syslog1-ctr logstash: {:timestamp=\>"2015-07-28T08:56:32.481000+0200", :message=\>"Exception in filterworker", "exception"=\>#\<TypeError: can't dup NilClass\>, "backtrace"=\>["org/jruby/RubyKernel.java:2064:in `dup'", "file:/opt/logstash/vendor/jar/jruby-complete-1.7.11.jar!/META-INF/jruby.home/lib/ruby/1.9/date/format.rb:833:in`\_parse'", "file:/opt/logstash/vendor/jar/jruby-complete-1.7.11.jar!/META-INF/jruby.home/lib/ruby/1.9/time.rb:265:in `parse'", "(ruby filter code):1:in`register'", "org/jruby/RubyProc.java:271:in `call'", "/opt/logstash/lib/logstash/filters/ruby.rb:38:in`filter'", "(eval):310:in `initialize'", "org/jruby/RubyProc.java:271:in`call'", "/opt/logstash/lib/logstash/pipeline.rb:262:in `filter'", "/opt/logstash/lib/logstash/pipeline.rb:203:in`filterworker'", "/opt/logstash/lib/logstash/pipeline.rb:143:in `start_filters'"], :level=>:error} Jul 28 11:44:55 syslog1-ctr logstash: {:timestamp=>"2015-07-28T11:44:55.666000+0200", :message=>"Exception in filterworker", "exception"=>#<TypeError: can't dup NilClass>, "backtrace"=>["org/jruby/RubyKernel.java:2064:in`dup'", "file:/opt/logstash/vendor/jar/jruby-complete-1.7.11.jar!/META-INF/jruby.home/lib/ruby/1.9/date/format.rb:833:in `_parse'", "file:/opt/logstash/vendor/jar/jruby-complete-1.7.11.jar!/META-INF/jruby.home/lib/ruby/1.9/time.rb:265:in`parse'", "(ruby filter code):1:in `register'", "org/jruby/RubyProc.java:271:in`call'", "/opt/logstash/lib/logstash/filters/ruby.rb:38:in `filter'", "(eval):307:in`initialize'", "org/jruby/RubyProc.java:271:in `call'", "/opt/logstash/lib/logstash/pipeline.rb:262:in`filter'", "/opt/logstash/lib/logstash/pipeline.rb:203:in `filterworker'", "/opt/logstash/lib/logstash/pipeline.rb:143:in`start\_filters'"], :level=\>:error}

If, yes, what it is and how can I solve it, please ?

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**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:** [July 28, 2015, 12:13pm UTC](https://discuss.elastic.co/t/logstash-error-exception-in-filterworker/26406/2 "2015-07-28T12:13:47Z")

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You seem to have a ruby filter that doesn't respond well to certain events.

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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:** [July 6, 2017, 5:33am UTC](https://discuss.elastic.co/t/logstash-error-exception-in-filterworker/26406/3 "2017-07-06T05:33:37Z")

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