Hi geekmidget, select the inner cone piece and then run the merge command on it (press tab key to put focus in XYZ bottom input that works like a mini command line, then type merge and then <enter>).

Then there will be just one edge on each object, select those and then you can do Blend.

When there are more than 2 edges and they are all touching each other end to end Blend will have some difficulty in automatically sorting them.

- Michael

You have 2 edges against only one on the surface so.. :) and Micheal is always more speedy than me! :)

And because i don't remember the Merge method :)
so my long method :)

Move Extract the 2 edges + the close circle Edge
Join the 2 edges it's now 2 curves !
Straight Loft the 2 Curves
Replace this repair against the false original



Here with Blend no problem after repair!

Awesome, thank you both!