请问打开launch文件报如下错 怎么解决呢？

[yinflight]

ERROR: cannot launch node of type [car_model/track_publisher]: Cannot locate node of type [t
rack_publisher] in package [car_model]. Make sure file exists in package path and permission
is set to executable (chmod +x)
ERROR: cannot launch node of type [car_model/simulator]: Cannot locate node of type [simulat
or] in package [car_model]. Make sure file exists in package path and permission is set to e
xecutable (chmod +x)