I noticed by doing some tests with models created in PTC Modeling that not all the elements of the .step file are imported, this even if the model is very simple (generally only one of the components is imported).
Unfortunately, I cannot give more precise information because the model was created from a friend since I do not have the software in my office.
I have attached the .step file. I hope it is sufficient to trace the problem.
Model created:
Model imported in PrePoMax:
As a side note, the import into PrePoMax occurs correctly if the .step file is imported into Solidworks and then re-exported as a .step.
This is not exactly a problem since a solution is already there (Solidworks or FreeCAD), but I thought I’d point it out anyway because this problem is present only in PrePoMax.
Here the step (Microsoft OneDrive)