I would add that it is doing something as there is a list of elements that I recognise on the RHS of the viewer together with these error messages (hence me wondering if it is a version issue). Or should it be one of the R (revision?) types R14, R13, R12, R10 or R9? Should I select an ASCII or Binary format?

Can someone let me know what the most appropriate version of the DFX file is that I should use? I am using ODA File Converter. I am trying to import a file from AutoCAD by converting it first to DXF format but there appear to be many options for the DXF type. I am a new user and am trying to see how LibreCAD works relative to my ancient copy of Autocad (2012).