error message on dashboard

maps works, but I got this error multiple times:

That address couldn't be geocoded, please make sure that it's correct.
Geocode response:
stdClass Object
(
    [error_message] => You have exceeded your daily request quota for this API. We recommend registering for a key at the Google Developers Console: https://console.developers.google.com/apis/credentials?project=_
    [results] => Array
        (
        )

    [status] => OVER_QUERY_LIMIT
)