# Access to MDM server blocked

Last updated: July 24, 2026

## Problem

On clicking **Sync** from the ManageEngine MDM Self Service app (previously ManageEngine MDM app), to reach the MDM server, the error message, **Access blocked! Contact IT Admin** is shown.

## Cause

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

- [Server is inactive](https://www.manageengine.com/mobile-device-management/kb/mdm-access-to-server-blocked.html#Restart).
- [Server is blocked by your organization's firewall or filter](https://www.manageengine.com/mobile-device-management/kb/mdm-access-to-server-blocked.html#Ensure).

## Resolution

- Restart the server and try **Sync** again.
- Ensure that the required [ports](https://www.manageengine.com/mobile-device-management/faq.html#g1) and [domains](https://www.manageengine.com/mobile-device-management/faq.html#g2) are allowlisted on the firewall/filter.

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