This server has once deployed another application with new relic license key
When deploying a new application, the debug log shows that the license of another application is being used
The configuration code is as follows

common: &default_settings
  # Required license key associated with your New Relic account.
  license_key: '25905xxxxxxxxxxxxx04b6'

  # Your application name. Renaming here affects where data displays in New
  # Relic.  For more details, see https://docs.newrelic.com/docs/apm/new-relic-apm/maintenance/renaming-applications
  app_name: 'xxx sandbox'

  # To disable the agent regardless of other settings, uncomment the following:
  # agent_enabled: false

  # Logging level for log/newrelic_agent.log
  log_level: debug

# Environment-specific settings are in this section.
# RAILS_ENV or RACK_ENV (as appropriate) is used to determine the environment.
# If your application has other named environments, configure them here.
development:
  <<: *default_settings
  app_name: 'xxx (Development)'

test:
  <<: *default_settings
  # It doesn't make sense to report to New Relic from automated test runs.
  monitor_mode: false

staging:
  <<: *default_settings
  app_name: 'xxx (Staging)'

The output log is as follows (sometimes using the license in the configuration, sometimes using the license of another application)

[2017-04-27 22:24:55 -0700 sandbox.aviagames.com (1183)] DEBUG : Sending request to collector-213.newrelic.com:443/agent_listener/14/7424fbxxxxxxxxxxxxx4bd/get_agent_commands?run_id=216855451632610815&marshal_format=json with POST
[2017-04-27 22:24:55 -0700 sandbox.aviagames.com (1183)] DEBUG : Received response, status: 200, encoding: ''
[2017-04-27 22:24:55 -0700 sandbox.aviagames.com (1183)] DEBUG : Received get_agent_commands = []
[2017-04-27 22:24:55 -0700 sandbox.aviagames.com (1183)] DEBUG : No thread profiles with data found to send.
[2017-04-27 22:24:55 -0700 sandbox.aviagames.com (1183)] DEBUG : EventLoop: Dispatching event 'report_event_data' with 1 callback(s).
[2017-04-27 22:24:55 -0700 sandbox.aviagames.com (1183)] DEBUG : Sending analytic_event_data to New Relic Service
[2017-04-27 22:24:55 -0700 sandbox.aviagames.com (1183)] DEBUG : EventLoop: Dispatching event 'reset_log_once_keys' with 1 callback(s).
[2017-04-27 22:25:20 -0700 sandbox.aviagames.com (1103)] DEBUG : EventLoop: Dispatching event 'report_data' with 1 callback(s).
[2017-04-27 22:25:20 -0700 sandbox.aviagames.com (1103)] DEBUG : Sending data to New Relic Service
[2017-04-27 22:25:20 -0700 sandbox.aviagames.com (1103)] DEBUG : Sending 31 items to metric_data
[2017-04-27 22:25:20 -0700 sandbox.aviagames.com (1103)] DEBUG : Sending request to collector-252.newrelic.com:443/agent_listener/14/25905dxxxxxxx04b6/metric_data?run_id=201836671014945180&marshal_format=json with POST