AdWords API v201509 will be sunset on June 21, 2016, after which all v201509 API requests will begin to fail. This version was 
deprecated on February 2, 2016. If you are still on v201509, we recommend that you skip v201601 and migrate directly to 
v201603. Please be sure to migrate prior to sunset to ensure your API access is unaffected.
We've prepared various resources to help you 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