non-manifold boundary at node ???

Mark

Hey,

im meshing a dart in Icem using a blocking approach. However, when i go to create my o-grid around the volume which makes up the solid part of the dart, i get this error.

The nose is blunt, and to do away with 7 noded hexa, i have split the nose block with an o-grid on the tip surface.

I get the error when i do the o-grid for the entire geometry. I dont know why, as there doesnt seem to be anything untoward. What does the error even mean, as the help files and google yield little.

Regards, Mark