Error message:

ERROR: cannot launch node of type [hector_mapping/hector_mapping]: Cannot locate node of type [hector_mapping] in package [hector_mapping]. Make sure file exists in package path and permission is set to executable (chmod +x)
                process[base_to_laser_broadcaster-3]: started with pid [25073]
                ERROR: cannot launch node of type [hector_trajectory_server/hector_trajectory_server]: Cannot locate node of type [hector_trajectory_server] in package [hector_trajectory_server]. Make sure file exists in package path and permission is set to executable (chmod +x)
                ERROR: cannot launch node of type [hector_geotiff/geotiff_node]: Cannot locate node of type [geotiff_node] in package [hector_geotiff]. Make sure file exists in package path and permission is set to executable (chmod +x)

When I tried to launch the hector slam tutorial launch file I got an error so I tried to go inside the hectorslam package and change some nodes to executables like the error message suggested I tried looking for for the hectormapping node inside the hector_mapping package but i could not find it in the src folder but for the other two packages I could find the node in the src folder so I made them executable by using the command chmod +x ~~~~~~ so then I tried running the launch file again and i noticed I got the same error I can't really find anything so i was wondering if i could get some help thank you