# Invalid Security Certificate

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, **Invalid Security Certificate! Contact IT Admin** is shown.

## Cause

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

- [SSL certificate](https://www.manageengine.com/mobile-device-management/help/configuring_mobile_device_manager/import_ssl_certificates.html?sss)[ added to the server is incorrect.](https://www.manageengine.com/mobile-device-management/kb/mdm-invalid-security-certificate.html#Click)
- [Device is connected to a proxy which prevents certificate validation.](https://www.manageengine.com/mobile-device-management/kb/mdm-invalid-security-certificate.html#Try)
- [Date on the device does not match with that on the server](https://www.manageengine.com/mobile-device-management/kb/mdm-invalid-security-certificate.html#Ensure).

## Resolution

- Click on **Verify Certificates** from the error message dialog box to initiate SSLPoke. This checks if the correct certificate is available in the truststore.
- Try **Sync** without using the device proxy.
- Ensure the dates on the device and the server match.

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