Thank you for sending the file. SAM can't calculate module parameters based on the electrical specifications you entered on the Module page for the CEC model with user-entered specifications. SAM uses a numerical method to generate the parameters that may fail under certain circumstances. We tested the method with all of the modules in the CEC library, so it should work with most commercially available modules.
Are the specifications you entered from a real module's data sheet? If so, could you either reply with a copy of the data sheet or tell me the manufacturer and model name so that I can look it up?
Best regards,
Paul.