To justify the display of the now famous (or rather infamous) “TrustedDWG” alert message, Autodesk claims that DWG files created by ODA’s DWGdirect libraries causes AutoCAD to become unstable. This is an excerpt from their initial complaint.
One problem with third parties’ implementations of the DWG format is potential data corruption resulting in instability introduced into the files by competitive products. Autodesk’s customer support personnel have logged numerous instances of Autodesk customers receiving DWG files from outsiders, then attempting to open the files with AutoCAD software, only to encounter serious errors.
In their reply, the ODA refuted by saying: “Autodesk has offerred no empirical evidence that its files are any more stable than others”. Indeed, they didn’t. And I wondered why, especially since any evidence, however small, could make their case rock solid. I investigated a little and came up with something truly interesting.
This is part of the DWGdirect 2.0.3 Release Notes (2.0.3 is the release in which the ODA added support for DWG 2007):
Bugs Fixed in 2.0.2
3565 DD writes DWG file which crashes AutoCAD.
3565 appears to the bug number and DD stands for DWGdirect. After digging more I found these bug fix entries for other DWGDirect releases:
1742 Linetypes with text are incorrectly saved to DWG.
2008 Acad crashes on a file saved by DD, containing an xref.
2211 AutoCad crashes on file saved by DDT – proxy issue.
2780 OdaMfcApp saves an invalid R12 file, which crashes AutoCAD.
2782 File saved to DXF 13 can’t be loaded by AC2004.
2783 File saved to DXF13 can’t be loaded by AC14.
2887 Acad crashes on attached file. DD audit/recover find no errors.
3150 Saved DXF file crashes AutoCAD.
The list goes on and on. Here we have the ODA (very honestly) admitting that their libraries cause AutoCAD to crash. They just shot themselves in the foot. Autodesk does not have to prove anything. The ODA did it for them.
This looks like clinching evidence to me. A smoking gun with lots of smoke. Its baffling why the Autodesk attorney’s didnt use it in their initial complaint. Could it be that they didn’t know about it? Seems hard to believe.