UPDATE 6/8/16: We have been receiving indications that this issue, while rare, may still exist on some devices.
Apple released iOS version 9.3.2 this afternoon. A notable fix for SimpleMDM customers is listed in the update notes:
“Fixes an issue that prevented MDM servers from installing Custom B2B apps”
Previously, iOS 9 had a bug that prevented Custom B2B VPP licenses from being assigned directly to devices using device-based license assignment. Devices would simply respond with a misleading “The iTunes Store ID of the application could not be validated” message.
As a workaround, MDM administrators were forced to use Apple ID User-based VPP assignment or redemption codes, the latter not being supported for devices and organizations in some countries. This bug affected all MDM solutions offering device-based VPP licensing support.
SimpleMDM is a mobile device management solution that helps IT teams securely update, monitor, and license Apple devices in a matter of minutes — all while staying on top of Apple updates automatically.