In order to reconstitute a manufacturer's library, I am trying to recover the sections of the metal joinery profiles available in DWG and summarized on the attached board.
I use drafsight 2021
I save the DWG of each profile that I want to recover in previous version (AutoCAD 2000)
Normally Solidworks can read dwg natively (but it doesn't like it too much as soon as there are a lot of strokes).
The best way to convert dwg / dxf files to an old version is DWG Trueview: it's totally free and made by autocad so it's really compatible with native files. You can even do batch conversion.
Quite a few warnings when opening your file with trueview. This may explain this...