Red dots appear while "Welding Verts" in T-Spline

Hi everyone. I know this topic must be in a relative forum but I don’t get how to solve it. I’m training with Jean Gorospe’s videos for learning T-Spline and have a problem with “Red Dots”. When I want to Bridge edges and Weld upside and downside verts together, red points appear and I can’t smooth it. I know that It’s a non-manifold but why? Welding two verts must be easy I guess…

3dm file:
Toy Plane.3dm (72.8 KB)


There are several faces and points intersecting each other that gives error. I fixed some => 3dm file :Toy Plane_2.3dm (542.1 KB)

1 Like

Thank you dear @Adn_Kocc for the time you put. Little changes fixed the problem and It is a solution way.