thanks for the reply.

if this is so >>

"The software has insufficient information to compute the proper contours to cap a non-planar closed curve."

Is there really no right way to close a "non planar nurbs edge hole" like in the picture?

The best answer I have found so far is convert it to a polygon mesh and forget about nurbs, but really? There is no real way to close a hole with nurbs? at all?