Irricad

I have just recently been getting the following error when importing DXF's from someone:

OpenDWG was unable to open
<filename.dxf>
OpenDWG Error #287
Viewport entity with no extended data -- invalid

Aborting File Translation . . .

Ive been unable to find exactly what this error actually means.
The file contains survey and drawing data from Autocad and notepad tells me the Autocad version is AC1021.

Any advice?

Hi,

The part of the error message which says "Viewport entity with no extended data -- invalid" is the clue. For some reason there is something strange about the layouts in this file and IRRICAD can't ignore them while trying to load the model. Open the file in AutoCAD or DraftSight and remove the Layouts. Save the file as 2012 or older format and try to import into a new IRRICAD design again.