On Friday, August 31, 2018, in accordance with the 
deprecation schedule, v201708 of the DFP API will be sunset. At that time, any requests made to this version will return errors.
If you’re still using this version, now’s the time to upgrade to the latest release and take advantage of fluid AdUnit sizes, Dynamic Ad Insertion options for video ads, and new reporting functionality.
In order to upgrade, check the 
release notes to identify any breaking changes, grab the latest version of your client library, and update your code.
Significant changes include:
This is not an exhaustive list, so be sure to check the release notes for a list of all changes. As always, don't hesitate to 
reach out to us with any questions. To be notified of future deprecations and sunsets, join the 
DFP API Sunset Announcements group and adjust your notification settings.