Jupyter Notebook: 404 : Not Found - You are requesting a page that does not exist!

If while accessing a Notebook on Jupyter on your web browser you see a 404 - Not Found error, then make sure that you are trying to access a valid page/notebook.

Fix/Solutions:

1. Just go to the homepage of Jupyter: http://localhost:8888/tree (default is 8888, may differ if changed, check the logs)

2. See the logs on the console and see if the directory from which the Notebook was serving is available and not deleted or moved.

Serving notebooks from local directory: /Users/c2ctechtv/Desktop/myproj2

3. If you visit http://localhost:8888/tree yet you see the same 404 Erorr, then try the following.

• Go to your Terminal/Command Prompt (depending if you are using Mac or Windows) where the Jupyter is running.
• Terminate the kernel by pressing Control + C
• Restart Notebook.

  python3 -m notebook

  [I 06:07:28.137 NotebookApp] The port 8888 is already in use, trying another port.
  [I 06:07:28.138 NotebookApp] Serving notebooks from local directory: /Users/c2ctechtv/Desktop/myproj2
  [I 06:07:28.138 NotebookApp] Jupyter Notebook 6.5.4 is running at:
  [I 06:07:28.138 NotebookApp] http://localhost:8889/?token=54e40f447444e0df392e94d5c6e2f389b6a756071a6e0300
  [I 06:07:28.138 NotebookApp]  or http://127.0.0.1:8889/?token=54e40f447444e0df392e94d5c6e2f389b6a756071a6e0300
  [I 06:07:28.138 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
  

• If there were any issues to start Notebook on the default 8888 port, it will be launched from 8889 or other.