ACIS entity check failure with imported object

Hey guys,

i am trieng to simulate a circular hornantenna with a lens. the horn antenna is designed with hfss and the lens is done by autodesk Inventor and then imported to hfss. now i want to simulate both. (Image attached).

My Problem: hfss does not like that the objects intersect and says that "ACIS entity check failed for part: Lens"

is it possible to solve that Problem or is it not possible to set the objects like i did?

thanks :)