Get configuration settings not working
The problem is in your flood_control.settings.yml.

flood_control:
  user_failed_login_ip_limit: 50
  ...


This way, to get user_failed_login_ip_limit you must use $this-&gt;config(flood_control.settings)-&gt;get('flood_control.user_failed_login_ip_limit'). Or just remove flood_control: on first line for better use.