If you are talking about QuickCAM 2D Design, then
If the outside edge of the tool goes outside the billet, it will generate a warning. This is because you may be using edge clamps that would be machined in to
It is just a warning though - and the CNC program will still be posted out - look for untitled.fnc, or the "name of the QuickCAM project".fnc in My Documents\Denford\CNC Files