From contour error

[Bep]

I have been unable to use the from contour tool.
What's wrong ? ,please give me some advise
Bep

UPDATE: I did something wrong with pasting from the ruby console
Now it is pasted correctly !

The ruby console shows this:

activated
Getting Sel Edges
In get sel edges
@ss.length=24
@totalEdges=24
@avgLength = 3.03158733129318
Starting work
In EdgesToPtArray
@ptSet.length=0
In CreateTerrain
pushing 1 on the end
removing non-functional
triangulating
Error: #<NoMethodError: undefined method []' for nil:NilClass> (eval):4361:in TriangulateDelaunay'
(eval):817:in CreateTerrain' (eval):877:in activate'
C:/Program Files/Google/Google SketchUp 7/Tools/Sandbox/SandboxMenus.rb:45:in select_tool' C:/Program Files/Google/Google SketchUp 7/Tools/Sandbox/SandboxMenus.rb:45 C:/Program Files/Google/Google SketchUp 7/Tools/Sandbox/SandboxMenus.rb:45:in call'