clone tool objects before subtracting hfss

Good morning to all. I am new to this forum and in HFSS (first design for me) and I have encountered a problem in my design. I am trying to draw a polyedron inside another polyedron (outside-->vacuum, inside-->perfect conductor) but I get the error message that the 3D model is incorrect because these two intersect. I have the design (I do not know if I am allowed to post it or s'th-i am new here) if my problem is not clear. Does anyone know what I should do to make that work? This (these 2 polyedrons) are supposed to be the SMA that will be connected to the patch I want to simulate. Any ideas???
thx in advance

ps. The word is NOT fix but "p a t c h" in the last sentence. In my pc I get the word fix instead so I am just letting u know!

Try subtracting the two objects and make sure to select "Clone tool object" before you do so or else you will lose part of the geometry.

HFSS does not like intersecting objects, even if the intersecting region is only 0.00000000001 m thick

Hope this helps.
Best Regards,
Vittal