Hi Nirma,
This error is happening prior to your model 'Faultag' simulating. You will have to take a look at the callback titled 'Set_parameters_R2018' that is causing this error.
I am unable to tell you why you experience this just based on the error message and without access to the files called by your model's callback, but what I would recommend doing is running your callback string outside of Simulink (either in the command window or an empty MATLAB script) to see if you still encounter the error and if so, see if the error message gives you a better idea of why calling 'Set_parameters_R2018' is erroring when using ff.
Sincerely,
Youssef
Edit: I forgot to mention this, but if you are still unable to determine how to prevent this error after examining the offending callback more closely, feel free to contact MathWorks Technical Support directly.
