Unable to sync ABM (VPP/DEP) apps and devices

Problem

On clicking Sync from the MDM server to reach Apple Business Manager (ABM) or Apple School Manager (ASM), for syncing devices or apps, the error messages, 'Failed to sync devices from ABM!' and 'Failed to sync apps from ABM!' are shown respectively.

Cause

The errors might be due to one of the following reasons:

• Apple Business Manager is blocked by your organization's firewall or filter.
• Apple services are unavailable.

Resolution

• Ensure vpp.itunes.apple.com, mdmenrollment.itunes.apple.com, and the required ports and domains are allowlisted on the firewall or filter.
• Check the status of Apple services and retry Sync.

If the problem still persists, contact mdm-support@manageengine.com (MDM On-Premises) or mdmcloud-support@manageengine.com (MDM Cloud).