Are you adding a new API key or updating an old API key?
If a new key did you add restrictions? if so the geocoding portion will not work with SLP version 4.9.14 or lower.
As a result of the Google API changes that will be in effect June 11, we are changing this in the next release (Version 4.9.15 )s this week . Once version 4.9.15 of SLP is released you will have the ability to add HTTP referrer restrictions if you also obtain the Google Geocoding Key
(The Google API key used for back-end geocoding of locations.)
In the meantime double check your key