1. Open the new TCW file.
2. Create any 3D object.
3. Create the view by going to View-> Named Views-> Create View.
4. Switch to paper space.
5. Go to View-> Viewports-> Viewport, select the created view, click on Go to and click on Close.
6. Save the TCW file as STEP by going to File-> Save As.
7. Whenever the imported STEP file is opened, viewport disappears from the paper space.
As Designed. TC STEP filter supports only 3D objects in model space.