I am using a demo of 2D/3D to draw simple 'layouts' for an iPhone cradle (as a learning exercise) and then export to DXF reading for import to VCarve Desktop and getting some very odd results and lots of open vectors. The work flow is this but have tried lots of variations.
ViaCAD latest version
Creating a simple 2D drawing using the rectangle and line commands, always snapping to the end of lines or intersects
Change to ISO view, 3D and extrude the parts I need (to create a tray for the phone).
Export as a DXF or DWG (tried both).
Import the drawing, OK- does everything I'd expect until I calculate the tool-path and dependent what type of cut I select depends on the open vectors it reports as being open, being ignored and closed. The preview screen what it thinks is correct but as you might expect nothing much like the drawing.
Using the tool to join vectors marginally helps.
Having tried so many different things now I'm at a bit of a loss but suspect that I am not doing things correctly in ViaCAD.