Export DreamPlan Project to STL for 3D Printing

[DragProt]

All, when exporting my project from DreamPlan using the File --> Export Project as 3D Model, the STL File export does not export the file into a printable 3D Format.  While the general structure is there and the interior walls are there in the exported STL File, they are simply "strings" and not a solid wall.  All the furniture, cars and other items in the model are simple outline strings, not actual sold printable 3D Models.  As an example, the walls are simply lines drawn as if they drew it on a flat surface in a zig-zag pattern.  This is not printable in any format.  I normally print things on 3D printers and have for several years.  Even putting the export into a mesh fixer like Audodesk Meshmixer and trying to fix the mesh is impossible as the surface area for the walls and other items are simply outline strings, not actual solid printable surfaces.  Anyone attempt this or is there some setting or other options which I've missed?  The help files for this type of export are very generic and don't offer any real options I can see.