help to find the error in rectangular patch antenna using hfss

While simulating the rectangular patch antenna following error will occur. Port refinement, process hf3d error: Failure in solving the ports.please help to solve this problem.

Hi,
Correct these things...
1) Patch is below the substrate, i.e Ground plane and patch are overlapping (It has to be 1.57mm above the substrate)
2) Select the faces for air box to assign radiation, not the whole object
hope this helps...

Thankyou ,i will try this