Warning 3DSketch25   Unable to offset one or more sketch entities.  I created a 3D sketch & extracted a surface intersection.  In the same sketch, I did a "convert entities" on one of the surfaces to get the edge curves & the warning above in red popped up.  What does the warning mean, & how do I correct it.  I'm at Michael.Piller@standardregister.com or ww2buffus@yahoo.com.  I'm working with surface models & viewed a couple of tutorials & was looking at trying some of the techniques shown in them.