help for a simple structure in CST

Hi

I try to determine the magnetic field over a very simple structure as a conductive plane with height h = 0.8 mm and dimension 50 * 50 mm with a hole in the middle of radius r = 1 mm in CST See attached figure. But I have never used CST and I get errors during the simulation
Can you help me solve this problem by giving me a correct structure

../imgqa/eboard/EM/EM-gscbgmdxnym.jpg



Thank you very much!