Google geocoding now seems to require an API key, settings page text needs update
The explanatory text on the geocoding settings page indicates that Google doesn't need an API key, but geocoding will no longer work without an API key:
(and I can verify that it does not work until you put in an API key). You also do need to enter your API key in the second set of fields (contra the text "You can leave the Geocoding fields blank if you are using Google as your mapping provider.")
Suggest changing the text on the settings page to reflect the update.