wave guide ports must be aligned with cartesian coordinate

I'm trying to simulate a differential trace in cst MWS using 2 waveguide ports with multipin selection[1(1+)(2+),1(1-)(2+)<=>2(1+)2(+),2(1-)(2+)], i have now this error "Waveguide ports must be aligned with cartesian coordinate planes for the transient solver" and i can't solve it, please help.

try tetrahedral.