error in HFSS simulation

Hi.I need help because I have faced a problem in simulation a design in HFSS.
I draw my design,define boundary conditions and excitations and I press Validation check button.It bears error:At least one material assignment should have solve inside set.I don't understand what it says.please help me.

Hello

This is mostly likely if you have solid boundaries and no radiation box defined.have you defined a radiation box for your design.try it and post your response

Regards
Elchachito

Thank you very much for response.I will try it and post the result.
May I ask another question?I want to design a cavity excited by a probe,I first draw a copper cylinder,subtract a vacuum with smaller dimensions from copper cylinder and then I draw a cylindrical probe inside the cavity where the vacuum has been subtracted.why does HFSS say that objects intersect?How can I dray this cavity with a probe in it?

when you draw the cavity and the probe.You have to do a simple thing if they are intersecting. go to toolbar---HFSS---design settings and check the box where it says" enable material override" problem should be solved

Regards
Elchachito