Having some issues with masses. Working with content from Autodesk Tutorial by Autodesk student experts form Graz Austria 2011, the operation is performed on the tutorial with relative ease however when I try it I get an error as follows: "This Mass has no solid geometry for its Void Forms to cut. They must be deleted, or solid geometry added and cut." However the voids intersect a mass? Also having an issue with view range, cutting a window, window sill not displaying. Seeking some expert advice.