Purpose

Some schools using Microsoft Defender for Endpoint may find that activatesoftware.exe or other Timetabling Solutions V10 executables do not open when users click Sign in to Activate.
This is caused by Defender’s reputation-based protection (SmartScreen) silently suppressing the activation tool.

Allowlisting Timetabling Solutions’ code-signing certificate as a Trusted Publisher resolves this issue for your entire organisation.

Why This Works

Microsoft Defender for Endpoint allows administrators to trust specific code-signing certificates.
Once a certificate is trusted:

  • Applications signed by that publisher will run normally

  • SmartScreen and reputation-based blocking are bypassed

  • Users no longer experience suppression or missing authentication windows

This is the recommended enterprise solution for schools.

Prerequisites

You will need:

  • Microsoft Defender for Endpoint

  • Access to the Microsoft Defender Portal (security.microsoft.com)

  • Timetabling Solutions’ current code-signing certificate (download link or copy supplied below)

If you need the certificate file, please contact Timetabling Solutions Support.

Steps to Allowlist Timetabling Solutions as a Trusted Publisher

1. Obtain the Certificate

Download the Timetabling Solutions code-signing certificate and save it locally.
(This will be provided on request if you do not already have it.)

2. Open the Microsoft Defender Portal

  1. Go to: https://security.microsoft.com

  2. Sign in with your administrator account.

3. Create a New Application Control Policy (or modify an existing one)

  1. In the left menu, go to:
    Settings → Endpoints → Attack Surface Reduction → Application Control

  2. Choose Allow or Allow-list rules depending on your existing configuration.

  3. Create a new Policy for Windows 10/11 devices (or edit your existing school-wide policy).

4. Add a Trusted Publisher Rule

  1. In the policy editor, select Add Rule → Publisher Rule.

  2. Choose Use certificate file.

  3. Upload the Timetabling Solutions code-signing certificate (https://timetablingmainsite.blob.core.windows.net/productupdates/Version10/TimetablingSolutions-CodeSigning-Feb2025-Feb2028.cer).

  4. When prompted, review the certificate details:

    • Publisher: Timetabling Solutions Pty Ltd

    • Issuer: DigiCert

    • Validity dates

  5. Set the rule action as: Allow

5. Assign the Policy to Relevant Device Groups

  1. Select the device groups that include staff machines running version 10.

  2. Save and apply the policy.

  3. Allow up to 30 minutes for policy propagation (varies by environment).

Verification

To confirm the allowlisting has worked:

  1. On an affected device, open V10 and click Sign in to Activate.

  2. The activation window should now appear immediately.

  3. No SmartScreen warnings or silent suppressions should occur.

If the executable still does not open, ensure:

  • The device is included in the assigned policy

  • The certificate used is the current Timetabling Solutions signing certificate

  • Defender for Endpoint is not enforcing a conflicting block rule

When to Update the Trusted Publisher Certificate

Timetabling Solutions renews its code-signing certificate in February 2028.
IT departments should:

  • Update the Trusted Publisher rule whenever a new certificate is issued

  • Remove expired certificates from your allowlist to reduce clutter

  • Contact us if you need advance notice of certificate rollover

We will notify schools as part of scheduled release communications.