Before
running your program, save all the files you changed, if you have
not already done so. You can choose File
Save All from
the VLISP menu, or use the ALT + SHIFT + S keyboard shortcut to
save all your open files.
The next thing you must do is reload all the files in VLISP.
To load and run all the files in your application
Open Project from the VLISP menu,
then enter the project file name gpath; do not
include the .prj extension. If VLISP does not
find the project file, choose the Browse button and choose the file from
the Open Project dialog box. Click Open.

Also, try drawing the path using both lightweight and old-style polylines. After drawing the paths, use the AutoCAD list command to determine whether or not your program is drawing the correct entity types.