Just a newbie so sorry, have 7.5, doing a tutorial, single poly walls, with boolean subtracts for windows, looks ok, except for the single line from corner to edge of extract, also when imported to another app, Vue, no extract shows. Also, if a multi poly wall, has same extracts, when imported to vue, extract shape has lost it's original shape?. LW 7.5, no patches , and Vue 4.12., win 2000 Ta. Pattie., images above.