CST 2010 Microstripes

Dear all,
I'm facing a problem with CST microstripes...Every time I run the TLM solver, the following error prevents me from getting the scattering parameters...
Error Number 921:Initial modes are used to establish a mode profile to launch into a port. The mode profile is calculated using initial conditions defined inside the initial mode. If initial modes are used theneach initial mode must contain at least one initial, all initials must be inside the initial modes. Check there is a well meshed gap between the conductors in the port...
Does anyone know what does this error mean?

Try to improve the resolution of the mesh.