Error corridor.add surface node (camber)

why node corridor.add surface l (when there are surfaces for the corridror) (the output…null)
when I use Autodesk…civil3dtoolkit nodes(such create profiles,alignments,corridors, …) when I pick run time after time there isn’t any error in node but in corridor surface if I press run for the fist time it is ok, but when I press the second time the error shows.


Can you show more of the graph?