# NameError: uninitialized constant Concurrent::ImmediateExecutor

**URL:** <https://discuss.elastic.co/t/nameerror-uninitialized-constant-concurrent-immediateexecutor/158027>\
**Category:** Logstash\
**Created:** [November 23, 2018, 2:48pm UTC](https://discuss.elastic.co/t/nameerror-uninitialized-constant-concurrent-immediateexecutor/158027 "2018-11-23T14:48:33Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![elkha](https://avatars.discourse-cdn.com/v4/letter/e/c77e96/32.png) [@elkha](https://discuss.elastic.co/u/elkha)\
**Post date:** [November 23, 2018, 2:48pm UTC](https://discuss.elastic.co/t/nameerror-uninitialized-constant-concurrent-immediateexecutor/158027/1 "2018-11-23T14:48:33Z")

</div>

I dont able to start and parse log file .  
I had an error when doing the command line : logstash.bat -f conffile.conf

NameError: uninitialized constant Concurrent::ImmediateExecutor  
const\_missing at org/jruby/RubyModule.java:2719  
Concurrent at D:/ELK-5.4.0/logstash-5.4.0/vendor/bundle/jruby/1.9/gems/conc  
urrent-ruby-1.0.0-java/lib/concurrent/configuration.rb:76  
(root) at D:/ELK-5.4.0/logstash-5.4.0/vendor/bundle/jruby/1.9/gems/conc  
urrent-ruby-1.0.0-java/lib/concurrent/configuration.rb:10  
require at org/jruby/RubyKernel.java:1040  
(root) at D:/ELK-5.4.0/logstash-5.4.0/vendor/bundle/jruby/1.9/gems/conc  
urrent-ruby-1.0.0-java/lib/concurrent.rb:1  
require at org/jruby/RubyKernel.java:1040  
(root) at D:/ELK-5.4.0/logstash-5.4.0/vendor/bundle/jruby/1.9/gems/conc  
urrent-ruby-1.0.0-java/lib/concurrent.rb:4  
require at org/jruby/RubyKernel.java:1040  
(root) at D:/ELK-5.4.0/logstash-5.4.0/logstash-core/lib/logstash/config  
/defaults.rb:1  
require at org/jruby/RubyKernel.java:1040  
(root) at D:/ELK-5.4.0/logstash-5.4.0/logstash-core/lib/logstash/config  
/defaults.rb:3  
require at org/jruby/RubyKernel.java:1040  
(root) at D:/ELK-5.4.0/logstash-5.4.0/logstash-core/lib/logstash/config  
/cpu\_core\_strategy.rb:1  
require at org/jruby/RubyKernel.java:1040  
(root) at D:\ELK-5.4.0\logstash-5.4.0\lib\bootstrap\environment.rb:70

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [December 21, 2018, 2:48pm UTC](https://discuss.elastic.co/t/nameerror-uninitialized-constant-concurrent-immediateexecutor/158027/2 "2018-12-21T14:48:43Z")

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