How to correctly simulate Stateflow state machine in a model that includes Sympower System blocks?

I'm working on a control algorithm for voltage regulation on three-phase power transformers. To implement the controller, I disigned a state machine usin the Stateflow toolbox of Simulink. The Stateflow block wakes up with every positive edge o a "Pulse Generator Block". When I press "Build Model" the next error shows up:

S-function 'PowerTest/Trafo # 1 45 MVA, 138 // 34.5 // 13.8 kV /OLTC R/Inversion de devanado/SwInv1/Model/Continuous/Sfunction' parameters must be of type double or char if the S-function does not have TLC

Note that this S-function block is allocated inside "SwInv1" which is an "Ideal Switch Block" of the Simscape toolbox, so is nothing of my doing.

This error seems to show only when I try to build the model with the "PowerGUI block" set in Continous mode. Unfortunatly, when I change it to Discrete mode, another error about difference in the sample time of the inputs and outputs of my Stateflow block shows up. Did I give enough information for somebody to make any suggestions?