There was a problem compiling the code from your notebook. Details: name 'parameters' is not defined

I don’t understand, everything run fine but when grading, I got 0 for the same error over and over, even the previous exercise where it’s not even needed

I suggest restarting the kernel and then running all the cells again.

Did you by accident uncomment a comment?
There the word parameters is used.

yeah, turn out I just need to make a new notebook and do it over again, and it did work