Course 4 Week 1 Assignment Technical Issues

Hello, I have experienced several technical issues while doing the first Assignment of Course 4 Week 1. Previously, I was unable to submit my assignment, because the Submission button was not present. Currently, I am facing a 404 Error. I deleted my assignment with the hope of refreshing it and bringing it back to normal but nothing changed. May I ask for your assistance.
Best,
Daniel

Did you rename the notebook file? That can cause problems with the grader.

Yes I did. I though I could keep track of progress in that way. I suppose, this made more harm than good. However, now that I have deleted the file I don’t know how to proceed.
Thank you for your reply though. Going forward, I will avoid remaining my files.

There is a thread linked from the FAQ Thread about how to get back a clean copy of the notebook.

Thank you for your quick response. I will definitely try it.