Not read saved files

[rocketsay]

Please help.
Autocad throws an exception, when I'm try to load dxf file, after savind with dxf.Save.
Firstly, I've tried to change the block of dxfInsert by changing the property Name. After saving I converted the new file into .pdf and everything was good. But I couldn't open this new file again with DxfFile.Load. So, I tried only Load file and Save file without editing, And I found the same exception "System.InvalidOperationException: The sequence contains no elements"

dxfFile = DxfFile.Load(path);
dxfFile.Header.Version = DxfAcadVersion.R14;
dxfFile.Save("012.dxf");

dxf files is attached.
Debug.zip

[rocketsay]

dxf.Header.SetDefaults();
dxf.ViewPorts.Clear();
dxf.Save("testp_1.dxf");

If I use just that, I can load file after saving, but it loses about 70% of data

[brettfo]

AutoCAD is very particular about what it will accept in a DXF file, and it can be difficult to make it happy.

It sounds like the issue is some object names getting out of sync with each other in the file. Can you modify your original example by adding a call to the Normalize() function right before you save like this:

 dxfFile = DxfFile.Load(path);
 dxfFile.Header.Version = DxfAcadVersion.R14;
+dxfFile.Normalize(); // <-- add this line; it attempts to bring everything back in sync
 dxfFile.Save("012.dxf");