Can't start simulator on rosject part 1

Hi. I just started working on the rosject part1, and as the instruction says I typed, “source /opt/ros/noetic/setup.bash”, “source ~/simulation_ws/devel/setup.bash”, and “roslaunch realrobotlab main.launch”. The Gazebo windows shows the simulation, however the terminal shows some errors, and I cannot proceed. I took a screenshot of the error being shown in the terminal. Could you tell me what is wrong? All I have typed so far are just the three lines of codes as I wrote above. I can’t see what can possibly go wrong within those three lines.

Hello @ATAT ,

Don’t worry about those error messages, just ignore them. They will not have any effect on your work.

Hi,

But the terminal cannot be used as long as there is this error message is being shown right? The instruction says to type more lines of code in the terminal. I waited for about 20 min last time to see if the terminal finishes its operation but it stays as it is with this error massage being the last line, so I had to do control C to quit the operation.

Hello @ATAT ,

Yes, you have to leave that terminal as it is (if you Ctrl+C it will terminate the simulation). To keep working and run more commands, you have to open another terminal. You can open an extra terminal on the Web Shell icon (bottom-left corner), by clicking on the + button, or in the terminal window itself, also clicking on the + button:

extra_shell

Best,

Hi,

I see. That makes sense. Thank you so much for your help!