Please note that there are new Apple software licensing terms that must be accepted by your DEP agent (the person who originally set up DEP for your organisation) before new iOS 11 devices can be assigned to your MDM server and configured out of the box.
Your DEP agent must login to your Apple deployment account to accept these new terms (https://deploy.apple.com).
If you don’t accept the agreements
- In ASM and DEP, you can’t assign new devices to your MDM server, even if you have selected the option to automatically assign new purchases to a specific MDM server.
Devices that were assigned to a Mobile Device Management (MDM) server in Apple School Manager or the Device Enrollment Program won’t be affected. If you Erase all content and settings on a device, the device is still assigned to the same MDM server and the same settings are applied during setup.
However, these conditions apply until the new agreements are accepted:
Apple School Manager instructors and managers can reset user passwords and send or print login information, but other site functions will be disabled.
Device Enrollment Program admins (other than the Agent) won’t be able to log into the Device Enrollment Program portal until the Agent accepts the updated agreements.
Your MDM server might report an error message like "403 T_C_NOT_SIGNED” when communicating with Apple’s device management servers.
More information is available at https://support.apple.com/en-us/HT203063