C1W2 Linear algebra course

Here’s a thread about that.

The TL;DR is:

  1. Rename your existing notebook
  2. Click “Help → Get Latest Version” and follow the steps there. That’s the Help in the upper right corner of the notebook window.

If you don’t rename or delete your notebook first, then nothing happens: the “Get Latest Version” procedure is specifically designed not to overwrite existing files so that people don’t accidentally lose their work.

All that is documented in great detail on the thread that I linked above.