Save-as dialog does not save files in .dxf format
Under Windows NT, the user can not use the .dxf suffix in the Save As dialog box. The program always uses the default .txt extension. Under Windows 95 the program works fine.
The behaviour of the GetSaveFileName() function changed between for Windows 95 and Windows NT. In WindowsNT, if the user doesn't specify the file extension, nFileExtension is 0, not the length of lpstrFile.
Solution / workaround
This problem is fixed in Cone Layout version 1.1. Please download this new version if you are experiencing the error above.