Can anyone possibly take a look at the linked file, that DataCAD 12 fails to open. DataCAD 11 runs it smoothly. The file is here: http://www.hirvesoo.ee/probleem/2ku.aec
The failure to open is being caused by a bug in DataCAD 12. It will be fixed in the update to 12.01.
If you reply with your email address, or send an email to techsupport@datacad.com, I can provide you with a copy of the file that will open successfully in DataCAD 12.