I am using script to set configuration parameters (for code generation) . Everything was fine except for one . Configuration parameters -> RTW -> interface -> combine signal /state structures: this parameter could not be set . y?

command used : set_param(Mdl_Name,'CombineSignalAndStateStructs','off'); %'on' | 'off' it shows error as follows :

</matlabcentral/answers/uploaded_files/29171/error.jpg> why does this error occur ? parameter name is correct .