Error upon assignment submission

Hi,

I am submitting the programming assessment from course 2 week 1 and running into an error.
My code is working in the notebook and meeting all the requirements and expected outputs.
The history.pkl is being given a grade of 50/50 but my assignment ipynb file keeps getting a 0/50. This is the error message I get on why it’s a 0/50: "There was a problem compiling the code from your notebook. Details:
list index out of range"

I would guess that your code works correctly for the unit tests in the notebook, but it doesn’t work correctly with the tests that the grader uses.

The “list index out of range” is a good clue. The grader tests your code with a different size of data.