I am trying to start training my robot and I am trying to run the following commands: 1)$ roslaunch turtlebot3gazebo turtlebot3stage_2.launch

Open another terminal and enter the command below.

2)$ roslaunch turtlebot3dqn turtlebot3dqnstage2.launch

If you want to see the visualized data, launch the graph.

3)$ roslaunch turtlebot3dqn resultgraph.launch

the 1st and the last commands run,but the second command gives me the following error :

[turtlebot3dqnstage3-2] process has died [pid 82651, exit code 1, cmd /home/cvpia/catkinws/devel/lib/turtlebot3dqn/turtlebot3dqnstage3 _name:=turtlebot3dqnstage3 _log:=/home/cvpia/.ros/log/6e03d914-b2b4-11ec-822b-fd031f661dd5/turtlebot3dqnstage3-2.log]. log file: /home/cvpia/.ros/log/6e03d914-b2b4-11ec-822b-fd031f661dd5/turtlebot3dqnstage_3-2*.log