Please HELP. Non-manifold edges found for part...

Hi all!
I'm a new-baby in using HFSS. I have a problem when creating a design of horn antenna. And I'm getting a error "Non-manifold edges found for part...". I don't know how to solve this problem.
I will really appreciate your comments.

Welcome qteks200,

I took a look at your file, but there are a couple of issues before I can answer your question:

1) What version of HFSS are you using?
2) Which design are you referring to? There are two in this file.
3) There aren't any analysis setups in either design. Can you please set these up to the point where you would run it normally.