[exploration_server_node-5] process has died

edit

Hello,

I am trying to run the frontier_exploration on ROS Melodic for my turtlebot3 burger but I am facing an error and a few warnings :

[ INFO] [1592915203.801508707]: global_costmap: Using plugin "obstacle_layer"
[ INFO] [1592915203.805797584]: explore_costmap: Using plugin "explore_boundary"
terminate called after throwing an instance of 'pluginlib::LibraryLoadException'
  what():  According to the loaded plugin descriptions the class frontier_exploration::BoundedExploreLayer with base class type costmap_2d::Layer does not exist. Declared types are  costmap_2d::InflationLayer costmap_2d::ObstacleLayer costmap_2d::StaticLayer costmap_2d::VoxelLayer polygon_layer::PolygonLayer

[ INFO] [1592915203.807513999]:     Subscribed to Topics: scan
[ INFO] [1592915203.826659128]: global_costmap: Using plugin "inflation_layer"
[ WARN] [1592915203.864713435]: local_costmap: Pre-Hydro parameter "static_map" unused since "plugins" is provided
[ WARN] [1592915203.865053590]: local_costmap: Pre-Hydro parameter "map_type" unused since "plugins" is provided
[ INFO] [1592915203.865672566]: local_costmap: Using plugin "obstacle_layer"
[ INFO] [1592915203.873300348]:     Subscribed to Topics: scan
[ INFO] [1592915203.884410664]: local_costmap: Using plugin "inflation_layer"
[ INFO] [1592915203.910916229]: Created local_planner dwa_local_planner/DWAPlannerROS
[ INFO] [1592915203.913519360]: Sim period is set to 0.10

[exploration_server_node-5] process has died [pid 557, exit code -6, cmd /home/madhushi/catkin_ws/devel_isolated/exploration_server/lib/exploration_server/exploration_server_node __name:=exploration_server_node __log:=/home/x/.ros/log/42335398-b534-11ea-ad57-6c2b5954a7e6/exploration_server_node-5.log].
log file: /home/x/.ros/log/42335398-b534-11ea-ad57-6c2b5954a7e6/exploration_server_node-5*.log

In frontier_exploration.yaml:

plugins:
  - {name: static,           type: "costmap_2d::StaticLayer"}
  - {name: explore_boundary, type: "frontier_exploration::BoundedExploreLayer"}
  - {name: sensor,           type: "costmap_2d::ObstacleLayer"}
  - {name: inflation,        type: "costmap_2d::InflationLayer"}