antenna designing using hfss antenna design kit

hi
i want to design a patch line fed ,and pifa antenna with a gain of 6 and operating frequency 900Mhz
but the problem is that when i give all the relative parameters and it gives me a ready to go design in hfss
it does not give any rsults and the port is also not assigned
i want to know that are there some post design steps as well if you are using ADK
and if there are some tutorials available please tell me i didnt find any on the internet