Plugin in the list but I can't use in the pipeline [ERROR]

Elastic Stack Logstash
1

Hello, I have installed a filter-plugin that I have created in a machine A, I have pack this plugin in a zip file to install it on a machine B that don't have access to Internet. When I install thix plugin with zip I don't have problem and the plugin appear in the list of plugin. But when I wan't to use this plugin in a pipeline I have this message :

"... error: Unable to load the requested plugin named elapsedStep of type filter. The plugin is not installed. ..."

The plugin that appear when I ask to list plugin :

logstash-filter-drop
logstash-filter-elapsed
logstash-filter-elapsedstep
logstash-filter-elasticsearch

The pipeline of Logstash that used elapsedstep plugin :

elapsedStep {
        unique_id_field => "file"
        start_tag => ["jobStarted","Etape1","Etape2","Etape3","Etape4","Etape5","Etape6","Etape7","Etape8","Etape9","Etape10",
                        "Etape11","Etape12","Etape13","Etape14","Etape15","Etape16","Etape17"]
        end_tag => ["Etape1","Etape2","Etape3","Etape4","Etape5","Etape6","Etape7","Etape8","Etape9","Etape10",
                    "Etape11","Etape12","Etape13","Etape14","Etape15","Etape16","Etape17","Etape18","jobFinished"]
        new_event_on_match => true
    }

The beginning of the code of the plugin elapsedstep :


class LogStash::Filters::Elapsedstep < LogStash::Filters::Base

  PREFIX = "elapsed_"
  ELAPSED_FIELD = PREFIX + "time"
  ...
  MATCH_TAG = PREFIX + "match"

  config_name "elapsedStep"

What can be the problem?