AdWords API v201502 will be sunset on November 12, 2015, after which all v201502 API requests will begin to fail. This version was 
deprecated on June 25, 2015. If you are still on v201502, we recommend that you migrate directly to v201509 (
released last week) and skip v201506. Please be sure to migrate soon to ensure your API access is unaffected.
We have prepared various resources to help with the migration:
As always, if you have any questions about this migration, please contact us via the 
forum or the 
Ads Developers Plus Page.
- Michael Cloonan, AdWords API Team