|Do not use a Google Maps API v2 key when loading the Maps API v3||Thor Mitchell (Google Employee)||9/20/11 11:00 PM|
As those of you who used the Google Maps API prior to the introduction of Maps API v3 no doubt recall, the Maps API v2 required that each developer obtain a "key", which was an 86 character long string starting with "ABQI" that had to be passed as the key parameter in the script tag that loaded the API into a page.
The Maps API v3 dropped this requirement, but we still see a reasonably large number of Maps API v3 apps that include a key parameter containing a Maps API v2 key when they load the Maps API v3. Until now the Maps API has silently ignored these key parameters, but in the near future we need to make a change that will cause any request to load the v3 API that includes a v2 key to fail.
If you develop or maintain applications using v3, please check that they do not include a v2 key in the script tag that loads the Maps API, and remove the key parameter from any that do so. If this does not affect you, but you regularly monitor this forum, please be aware that you may see some questions from developers about this. We'll be emailing the highest volume offenders directly, but there will inevitably also be many that do not hear about this change and respond to it before their apps stop working.
Google Maps API