I opened my OS model in SketchUp, and this message appeared to me:
Warning: Sub Surface 143 This sub surface was not in the same plane as its base surface. It has been automatically fixed.
Error: Sub Surface 143 This sub surface is not contained by its base surface, it cannot be drawn.
Very good. I just want to delete this subsurface, but it is not drawn in the model, so i cannot select it. If I use the Inpector, I can find it, but it's not possible to delete it. How can I do?