https://1drv.ms/u/s!AuCx5sy3SAgmyzguUHTJ2VErnlvf

[url=http://]https://1drv.ms/u/s!AuCx5sy3SAgmyzcsHVOVBfWWcyJk[/url]

In the two images, I have the original 3D Drawing of a door, and a screen shot of that same door when inserted into a wall in Sweethome3d. On the right hand door, I used Red, Green, Blue and Black for the different component groups.

i.e. The Jamb, Door, Hinges and Handles, Casing.

As you can see, when the door is inside the wall, a grey colored artifact appears, aligned with the panels in my doors. Can anyone give me a clue as to what is happening?

Many Thanks
Martin