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