During a migration from Google Sites to SharePoint, the migration, audit or the Get Sites command fails with the following error message:
Invalid URI: The URI scheme is not valid.

Cause 1

Two-step verification is enabled on Google.


Make sure to bypass ADFS or to disable Google two-step verification (instructions here) and relaunch your task.


Cause 2

The Google service account used for the migration doesn’t have permissions to access to the Google site.


Follow this article to set the permissions correctly:
Make sure to add all the necessary scopes to set the permissions.