[HFSS] Port refinement, process hf3d error: Port 1 is assigned to an internal face ?

I am simulating an Ungrounded Coplanar Wveguide with a wave port excitation in HFSS as shown below.

I am getting following error;
"Port refinement, process hf3d error: Port 1 is assigned to an internal face. Only allowed with lumped ports.. "

Any Solutions?
Regards

Hi kela3kela,

The location of your surface for the wave port must not be aligned exactly - the wave port must be right on the outer boundary. Everything else looks OK.

Thankyou for the reply. But to my understanding, it is on the outer boundary..

The message "Port 1 is assigned to an internal face." tells the opposite.

Ill try to keep the wave port boundaries in touch with the radiation box from the bottom (X-axis). Lets c what happens.

I have the same problem. some one help plz.

The original question has been already answered. I don't see which different answer could be given to your post unless you manage to describe your problem in detail and tell why the given solution doesn't help.

This is my design, my dimensions are correct , but I do not understand exactly ,why I receive the error.
also I do not understand the direction of wave port line . I did not set the wave port line direction.