Apple will be changing the Software License Agreement to the Device Enrolment Program along with iOS 11 release.
You need to log into your DEP account on the 19th of September and access the new terms in order for the DEP program to continue to function.
Official Apple comms below:
Apple Deployment Programs
Thank you for participating in the Device Enrollment Program. On September 19 Apple will release updated software license agreements. Your Program Agent must go to the deployment programs website and accept the following agreements to continue to use the program:
- Apple iOS Software License Agreement
- Apple tvOS Software License Agreement
- Software License Agreement for macOS High Sierra
For more information please see this support article: If Apple Business Manager, Apple Business Essentials, or Apple School Manager asks you to approve new terms and conditions - Apple Support