I ran the check command on part of my model and I get the error:
"Rhino polysurface object is not valid.
ON_Brep.m_T.m_bRev3d = false, but closed curve directions are opposite."
I ran the Dir command and all seems fine. So why does it complain that, “curve directions are opposite?”
I also ran the CheckEdges command with the show naked edges option and nothing looks strange. The highlighted edges are where this object joins to the rest of the model (which is hidden).