FEKO symmetry questions

Hello all,

I am attempting to design my a microstrip structure in FEKO using symmetry option to reduce the cost while running, because my structure is very big, 20*15 lambda2. However, I always get an error saying that the set up violates the symmetry and cannot calculate the S parameter. I believe I set the system coordinate in the middle of the structure, and the 2 halfs are symmetric. Do you have any idea or know any reason of this problem?

Thank you,

---------- Post added at 01:37 ---------- Previous post was at 00:12 ----------

Do you know where should I put the system coordinate?Is it the best way to put the origin of the coordinate in the middle(center) of the geometry?

Thank you,