decode or encode error，Can anyone help me? Thanks

[lhbose]

Hello, I have a question to ask. Thank you！
I have found several issues with DWG encoding and decoding, and I would like to know if it is due to my incorrect use?
Q 1: I am reporting a memory error using the dwg_write_file function, which occurred when I created versions of dwg for R_2007 and R_2004 using the dwg_new_Document function.

Q 2: When I use the dwg_new_Document function to create the R2000 version of dwg, there are no errors. However, when I use AutoCAD to open this file failed and report version incompatibility.
Remarks:
The versions of R2000, R2004, R2007, and others versions saved using the dwg_write_file function cannot be opened in AutoCAD and will report version incompatibility errors.
and i opened dwg file created with libredwg using qcad can works well,but while i save as an another dwg file,qcad reports an error: error while writing dimention style,requires an integer between 1 and 6.

// here is my testing-code
int
main ()
{
int error;
const char *out_file = "C:\Users\Administrator\Desktop\dwg\tmp.dwg";

// create an empty dwg file
Dwg_Data *p_out_dwg = dwg_new_Document (R_2000, 0, 3);

dwg_point_3d pt1 = { 1.5, 2.5, 0.2 };
dwg_point_3d pt2 = { 2.5, 1.5, 0.0 };
Dwg_Object_BLOCK_HEADER *hdr;
Dwg_Object *mspace = dwg_model_space_object (p_out_dwg);
hdr = mspace->tio.object->tio.BLOCK_HEADER;

// add a block to dwg
Dwg_Object_BLOCK_HEADER *blk;
blk = dwg_add_BLOCK_HEADER (p_out_dwg, "bloko");
dwg_add_BLOCK (blk, "bloko");
dwg_add_LINE (blk, &pt1, &pt2);
dwg_add_ENDBLK (blk);
dwg_add_INSERT (hdr, &pt1, "bloko", 1.0, 1.0, 1.0, 0.0);

// add a entity to dwg
dwg_add_CIRCLE (hdr, &pt1, 0.5);

// save dwg
error = dwg_write_file (out_file, p_out_dwg);

Dwg_Data in_dwg;
memset (&in_dwg, 0, sizeof (Dwg_Data));
error = dwg_read_file (out_file,&in_dwg);

printf ("DWG file read successfully.\n");

// free mem
dwg_free (p_out_dwg);

return 0;
}