Expert: Bill DeShawn - 12/21/2007

Question
when i want to copy a drawing or part of a drawing, i get this message that ARX_error:enotthatkindof class and nothing is done. i am using Autocad 2006 and saving into 2002. even if i save into 2004 i get the same message. what should i do to not get this message or when i get it how to fix it? thanks.

Answer
This is a common problem that appears when somebody receives a drawing file from somebody else who is using a version higher than their own.  I haven't seen a reliable repair for this myself.  However, theoretically, this is what is supposed to work.  The person that supplied you with the drawing, needs to send you the drawing in its original format instead of sending you the drawing saved back to AutoCAD 2004 format.  While you're waiting for that, you download and install DWG Trueview 2008 from this site:
http://usa.autodesk.com/adsk/servlet/mform?id=9078813&siteID=123112
When the drawing arrives, use DWG Trueview 2008 to convert the DWG to AutoCAD 2000/2000LT format.

This hotfix is for the people that supplied you with the 2000 format DWG that was saved back from 2007 on a system that lacked the hotfix before they sent it.  Here's the URL for them to install to their systems:
http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=7450124&linkID=...

There is nothing wrong with your system, and unfortunately there is no way for you to fix an already corrupt drawing.
With the DWG as messed up as it is, you can't even WBLOCK anything out to your local drive or network drive.  One thing you might be able to do is to DXFOUT to the Release 12 DXF format and then open that DXF file up with AutoCAD 2006 to see if that fixes the problem.  Hopefully, the older DXF format won't support the newer 2007 info and with the DXF file opened you will be able to create a new DWG file, fully capable of Copy, Cut, Paste, and WBLOCK commands.

Keep in touch
Bill DeShawn
http://my.sterling.net/~bdeshawn