reading r2000 dwg files with dwg_read_file hit some problems

[xth26]

My environment is windows 10, vs2019, using libredwg which was recompiled and installed with vs2019.
My original files are r2018 dwg files, so I need to convert to r2000 for libredwg to read properly.
I can read the r2000 dwg file normally by converting it with QCAD/CAM, but converting it to r2000 dwg file with ODA File Converter or AutoCAD gives me an error code of 68.
The reason for error code 68, as you answered before, is because of ARX sources.
Is the reason for the 68 error code when converting with AutoCAD or ODA File Converter also because of ARX sources?

[rurban]

My original files are r2018 dwg files, so I need to convert to r2000 for libredwg to read properly.

No you don't need to. libredwg can read all versions just fine.