Hello all,

I understand what you are saying about strucure 1 seeming to be split in 2. But that is only due to a missing recompute. Just mark it for recompute, then recompute it and the gap is filled and it is a normal box. Apparently a left over of my try and undo afterward. Sorry for the confusion.

After doing the recompute, Structure 1 and 2 are both rectangle boxes of different sizes again that intersect.

Select structure 1, ctrl+ select structure 2, hit substract, and you end up with structure 2 minus structure 1.

Selecg structure 2, ctrl+ select structure 1, hit substract, and you end up with structure 2 minus structure 1.

There is no way to create structure 1 minus structure 2 with the subtract fuction!

And of course I could use the boolean function from the part workbench, but that is not the point here.

There now is a thread with a similar issue on the Add function.

https://forum.freecadweb.org/viewtopic.php?f=23&t=34429
Possibly the 2 are related.

I have created a bug report on this one and mentioned the add problem there as well

https://www.freecadweb.org/tracker/view.php?id=3882
Kind regards,

Bert