calculating preliminary structural mass in MS modeler. some plates don't give a mass value?

dear maxsurf egent.

i have a problem getting the mass value for some plates in my design model. i have created all the plates using the method " Plating a Whole Surface." see attached picture below.

also, why i see only plates on one side of the ship? surface model is created symmetrical and i have modelled only one side.

thanks for advance

ragnar