Just in case, anyone trying the most basic sample and seeing a corrupt basemap, here's an explanation and the solution.
Steps to reproduce
- Use a recent version of Chrome or Firefox (other browsers not tested)
- Navigate to https://notebooks.esri.com
- Create a new notebook (New -> Python 3)
- Enter the following script code
from arcgis.gis import *
gis = GIS()
- Run the cell (<Ctrl-Enter>)
- The result looks similar to this:
Instead of using the secured https connection, use http://notebooks.esri.com instead. As everything will be loaded without encryption, Chrome / Firefox are happy with that.
However: If you change your script to an authenticated AGOL-Session, you will send your username / password in plain-text through the net!
Both Chrome and Firefox have the option to explicitly allow loading unsecure content. In Chrome, there's a small icon on the right, in Firefox, it's right beside the https-indicator.