Fail to Parse Timestamp:Class of Logstash.

[acro-tanaka]

• Version: logstash-5.1.2、
• Operating System: linux
• Config File (if you have sensitive info, please remove it):
  input {
  salesforce {
  client_id => 'xxxxxxxx'
  client_secret => 'xxxxxxxx'
  username => 'xxxxxxxx'
  password => 'xxxxxxxx'
  security_token => 'xxxxxxxx'
  sfdc_object_name => 'xxxxxxxx'
  }
  }

output {
stdout {
codec => rubydebug
}
}

• Sample Data: Salesforce
• Steps to Reproduce: Run logstash with the config file.

Sending Logstash's logs to /home/ec2-user/logstash-5.1.2/logs which is now configured via log4j2.properties
[2017-01-25T04:47:57,197][INFO ][logstash.pipeline ] Starting pipeline {"id"=>"main", "pipeline.workers"=>2, "pipeline.batch.size"=>125, "pipeline.batch.delay"=>5, "pipeline.max_inflight"=>250}
[2017-01-25T04:47:57,215][INFO ][logstash.pipeline ] Pipeline main started
[2017-01-25T04:47:57,272][INFO ][logstash.agent ] Successfully started Logstash API endpoint {:port=>9600}
[2017-01-25T04:47:58,737][ERROR][logstash.pipeline ] A plugin had an unrecoverable error. Will restart this plugin.
Plugin: <LogStash::Inputs::Salesforce client_id=>"xxxxxxxxxxxxx", client_secret=>"xxxxxxxxxxxxx", username=>"xxxxxxxxxxxxx", password=>"xxxxxxxxxxxxx", security_token=>"xxxxxxxxxxxxx", sfdc_object_name=>"Opportunity", id=>"xxxxxxxxxxxxx",
enable_metric=>true, codec=><LogStash::Codecs::Plain id=>"xxxxxxxxxxxxx",
enable_metric=>true, charset=>"UTF-8">, use_test_sandbox=>false, to_underscores=>false>
Error: undefined method `parse' for LogStash::Timestamp:Class
^C[2017-01-25T04:48:02,512][WARN ][logstash.runner ] SIGINT received. Shutting down the agent.
[2017-01-25T04:48:02,527][WARN ][logstash.agent ] stopping pipeline {:id=>"main"}