STL to CNC Luban 4.0.1 issue

hi everyone

just wanted some help to test these 2 stl files, and why i cant get an toolpath generated for file 2.

file 1, works and both toolpath and preview showes when i export the gcode to the workspace
1-coster-flip project.stl (199.9 KB)

file 2, has an issue , the toolpath doesn’t generate , but the preview shows the final outcome.
2-Trivet-Procedural-Voronoi-Structure.stl

tried this with different stl file and im not sure why it wont work with some files.

i want to use luban stl to carve , since its simple and strait forward for some jobs.

did you face the same issue with stl files and how did you address this ,
thx