And how to subtract roads from the wood? It is easy... in v. 8.6 – just apply the Subtract Polygons utility. The operation is more difficult in earlier versions…
The point is that Shears (the main cutting tool) was repeatedly improved and alternated. It got new abilities from one version to another:
- An existing contour may be selected as a cutting frame at pushed Ctrl key;
- Shears «snatch» borders of polygons selected with Group Editor;
- Explicit specification of layers that may be cut became possible;
- Significant acceleration of cutting-out of holes;
- «Self-annihilation» of nested polygons on the cutting frame layer is corrected.
I don’t remember now in what version one or another improvement was done.
First of all you must specify exactly what to cut. Switch off all unnecessary layers and FREEZ the cutting one to avoid its self-distraction.
Or select the “victim” layer explicitly in the Parameter Bars of the Shears tool.
Create cutting frames or just select them (if possible) with the Group Editor and press Alt+W. Otherwise select the contours with the Shares holding the Ctrl key pushed. It is better to do in several movements. Make the cutting polygons transparent and polygons on the underlying layer – filled to see where holes will be.

Make a copy of the ENTIRE PROJECT FOLDER including DB before cutting necessarily. Something may go wrong at first attempt!