Error: "Failed to retrieve license (HTTP 401)

I’ve been trying to follow the getting started tutorial here, but I can’t do this section in step 4. The page says:

To upload it to your board, press the ‘Upload ’ button (arrow right) near the dropdown. A ‘BUSY ’ label replaces the buttons during code verifying and uploading. If the upload is successful, the message “Success: Done uploading ” will appear in the bottom output area.

I clicked the right arrow button, it said BUSY, but then I get this error:

Can anyone help me out? I’ve got an Arduino Uno and I’m using the web editor on Chrome OS (I installed the extension).

I am getting a similar error but with "failed to fetch".

Any ideas on why I would have students getting this error?

Thank you,