Grader error:problem compiling the code from notebook

[ashleyliu31]

For the C1_W3 assignment, I passed all the w3 unit tests in the notebook and all my outputs match the expected values, but when I submit my assignment for grading, every exercise gives this error:

There was a problem compiling the code from your notebook. Details:
name ‘n_x’ is not defined

I checked the code in the notebook and don’t think I accidentally deleted something essential. I ran the entire code in the notebook and received no error. Any thoughts?

Update: after doing some research on this issue, I think the problem might have been caused by me accidentally deleting a cell that shouldn’t be deleted. Where can I find the original assignment file so I can see all the original cells and code before all my editing?

[Kic]

Hi @ashleyliu31 ,

The kernel can become out of sync, especially after a period of inactivity. That is reason why you should always rerun your code every time you login and start working on the notebook. When you rerun all the code, the kernel is now up to date, so the error has gone away.

If you still need to get a fresh copy of the, here is one of the topics under the FAQs.