Hello everyone,

I have been working on the A/B testing assignment from Week 4.

When I submit my assignment I get 0 points on each one of the items. The grader feedback says there was a problem compiling from my notebook: unsupported format string passed to NoneType.format

I have already tried getting a fresh notebook, saving before I submit and looking at the metadata. The metadata shown in the grading cells is:
“tags”: [
“trusted”: true
I have ran out of things to try so I am reaching out in case anyone can provide any assistance.


Quite a lot of things can cause this.

First, did you complete the entire notebook? If you leave any “None” statements, it will make the grader crash. You can’t grade an incomplete notebook.