Dear Klemens
First of all: the Google updated the License for Google Map APi use.
So, you need recreate your Map Api key.
developers.google.com/maps/documentation/javascript/get-api-key
also this error may appear if you add address which google can't understand.
as example: you try find location by "Zip code" - "81699" - in world exist many location with this zip code.
Regards
Andrew
Ordasoft team