Grader error:problem compiling the code from notebook

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.