I have attached an image showing the error I am getting. The error is happening when building a state machine that contains several linked atomic subcharts. I define the parameters via a MATLAB script that is run before building the model. The script creates 'Simulink.Parameter' objects. So far I have determined that the error occurs if a parameter is required by one of the atomic subcharts (via the subchart mapping) but is not defined in the main chart. I have spent a considerable amount of time ensuring that this is not the case but I still have two instances of this error. I am posting this question to verify if there are other reasons that might trigger this error. Any help would be greatly appreciated.