Problem executing roslaunch

I am applying the example of basic ros in 5 days on my pc and the following error occurs to me, could you please help me on how I can solve it, thanks
ERROR: cannot launch node of type [simple_pkg/]: can’t locate node [] in package [simple_pkg]

Hi Brayan,

This error means that you should make the file executable by running:

chmod +x

By the way, is it the ROS Perception course or the ROS Basics course? You have created this post on the Perception course.