Hi TeraWatt,
It appears to me that you are having trouble in debugging the powergui block. Setting “breakpoints” in Simulink is one method of error debugging.
Kindly refer the below documentation to know more about how to debug simulation using breakpoints in Simulink: https://www.mathworks.com/help/simulink/ug/conditional-breakpoints.html
Best Regards,
Abhishek Chakram