Script doesn't work while inside ACT Extension

I'm trying to create a Workbench Mixed Wizard, to analyze a simple cantilever beam.
I managed to make the geometry generation script to work for any SpaceClaim instance I open as standalone. Although, when it's part of a step of a Wizard, I get the following error:

I feel like I should import the SpaceClaim scripting capabilities into the extension, but don't know how. ACT developer's guide didn't help much.

Appreciate any help!
Paulo Libório.