Notebook won't connect to Portal

[dgiersz_cuyahoga]

When creating a gis.map in a Notebook in Pro, if using our Portal, it loads the map but shows a popup displaying 'Error while authenticating to portal on first load. See the browser console for more info.'

Them I am unable to add any Portal Items to the map.

Also, after every attempt, the Portal logs show:

Generate Server Token failed, serverId not found

Server URL can't be validated for granting server token 'https://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer'

Anyone know how to fix this?

I'm using Pro 2.9.2 and we have AGE 10.9.1

Thanks!

[dgiersz_cuyahoga · Accepted solution]

This was caused by the AllowedOrigins settings in both Portal and Server.

The Portal AllowedOrigins was blocking the initial authentication, causing the error above. 

The Server AllowedOrigins was blocking the adding of layers to the map.