when i am runing the logstash conf
i am getting this exception
someone know why?
ATAL] 2018-02-08 14:14:59.163 [main] runner - An unexpected error occurred! {:error=>#<TypeError: no implicit conversion of nil into String>, :backtrace=>["org/jruby/RubyFileTest.java:96:in directory?'", "org/jruby/RubyFileTest.java:88:indirectory?'", "/etc/logstash/logstash-core/lib/logstash/settings.rb:469:in block in value'", "org/jruby/RubyKernel.java:1741:intap'", "/etc/logstash/logstash-core/lib/logstash/settings.rb:468:in value'", "/etc/logstash/logstash-core/lib/logstash/settings.rb:65:inget_value'", "/etc/logstash/logstash-core/lib/logstash/environment.rb:91:in block in LogStash'", "/etc/logstash/logstash-core/lib/logstash/settings.rb:126:inblock in post_process'", "org/jruby/RubyArray.java:1734:in each'", "/etc/logstash/logstash-core/lib/logstash/settings.rb:125:inpost_process'", "/etc/logstash/logstash-core/lib/logstash/util/settings_helper.rb:26:in post_process'", "/etc/logstash/logstash-core/lib/logstash/runner.rb:223:inexecute'", "/etc/logstash/vendor/bundle/jruby/2.3.0/gems/clamp-0.6.5/lib/clamp/command.rb:67:in run'", "/etc/logstash/logstash-core/lib/logstash/runner.rb:219:inrun'", "/etc/logstash/vendor/bundle/jruby/2.3.0/gems/clamp-0.6.5/lib/clamp/command.rb:132:in run'", "/etc/logstash/lib/bootstrap/environment.rb:67:in'"]}
[ERROR] 2018-02-08 14:14:59.181 [main] Logstash - java.lang.IllegalStateException: org.jruby.exceptions.RaiseException: (SystemExit) exit