"File Load Error for...Invalid response: 404 Not Found" when loading .ipynb on Spyder Notebook

Question

I am using Spyder v6 and I am trying to load a .ipynb file using the Notebook plugin. The Notebook plugin is successfully installed, since I can see the Notebook interface when I open Spyder.

However, when I try to load the .ipynb file I do get the following error:

File Load Error for test_file.ipynb
Invalid response: 404 Not Found

I checked that the problem was not with the .ipynb file by opening it with jupiter notebook and it worked. So I guess the problem is with Spyder.

The file I am trying to load can be download from here: https://github.com/dnanexus/OpenBio/blob/master/UKB_notebooks/ukb-rap-pheno-basic.ipynb

Note that Spyder was installed using conda on a specific environment.