I'm really struggling with this.
I can import a dxf, but it refuses to treat it as a board outline. There is an import error which says:
Warning (line 6924): Board Outlines must be closed and non intersecting. Some shapes of these types have been created.
These have been removed and replaced by open shapes on a non-electrical layer.
End Of Report.
Here is a rough png so you can see the shape of the board:
If I try to convert the shape to a board, then behaviour changes depending on which section of the shape I select. If I change the shape type of either the left or right hand edge, then I see a slim green rectangle like this:
If I try to change the shape type of anywhere else I get an error:
Although the DXF looks fine, there is clearly something that DSPCB does not like. Does anyone have any idea what it is?