It is a great service getting an email like this from Autodesk. But you have to have CIP activated to have this working.
Dear AutoCAD® Customer:
Autodesk has recently released a Technical Solution for your product. Errors similar to those you have encountered have been resolved by the following Technical Solution.
We recommend that you apply this Technical Solution, or contact your system administrator.
Error Report Summary
Date The problem title you provided Autodesk
2008-04-18 I was in Open dialog box and selected a file to...
2008-03-17 Tried to open a drawing
Fatal error or unhandled exception when opening or closing a drawing file
These errors may be caused by the digital signature feature.
To correct this issue
- In Windows Explorer, right-click on a drawing file. On the shortcut menu, click "Enable/Disable Digital Signature Icons."
- Clear the "Validate digital signatures and display special icons" check box.
- Reboot the system.