Object made with Loft cannot be exported to Flow Design

At the moment I am busy trying to create a Blended Wing Body. To test my designs I use Autodesk Flow Design. Unfortunately, this program does not accept .dwg so it is needed to change these files to .slt. The problem I encountered while doing this is that objects made with the Loft functions will not appear in the simulator and cannot change into .slt in contrary to the other AutoCAD-made objects which are transferring successfully.

Does someone know how I can change these Loft-objects to non-Loft objects in order to successfully change them to .slt?

I moved your thread to the AutoCAD 3D Modelling & Rendering Forum.

Did you mean .stl?

It has been a while since I converted anything to .stl, but I never had a problem with lofted objects not converting.

Have you tried using a different file format, the site shows it accepts .dwg, .fbx, etc.?

Can you post a part of the drawing that you are having trouble with?