Modeling microstrip patch in FDTD with edge port

In the attached CADFEKO file modelling a microstrip line with a defective ground plane using FDTD solver. When I tried to mesh the geometry I get the below error message 

I tried defining a local mesh for the geometries where the port 1 and 2 is located, but the number of voxels increases considerably. Can you please look at the model and let me know how to model the structure using FDTD solver