Even though I have passed all the test cases in the notebook, my submission got 0 score. I could not even re-do the assignment since the notebook cannot be loaded for a week so far. I badly need some helps with this technical issue otherwise, I cannot complete the tasks for the 1st week.
It looks like you must have damaged the notebook in some way. So you need to get a clean copy. The problem is that you need to be able to rename the notebook before that can be done. Try doing “Help → Lab Help → Reboot Server” and see if that gets the ability to access the “File” menu of the notebook.
If you can get the notebook to load, then click “File → Rename” and rename the notebook. Then do “Help → Lab Help → Get Latest Version”.
Actually here’s another method: it turns out to be a lucky thing that all 3 of the assignments in Week 1 of Course 2 are in the same Docker image. So you can rename the Regularization notebook from one of other assignments in Week 1. E.g. open the Initialization assignment again. Then click “File → Open” to get to the file navigation view. Then go up to the folder one level higher and click down into the W1A2 subfolder. That’s the folder for the Regularization assignment. Now use “File → Rename” to rename the main ipynb file there.
Now go back to the Regularization assignment and click “Work in Browser” again. You’ll get a 404 error, because the notebook is no longer there. But you can still do “Help → Lab Help → Get Latest Version” and that will get you a clean copy. There’s a more detailed explanation of that procedure linked from the FAQ Thread.
Thank you very much for the detailed instruction. It works and I could get the assignment done.