Why Cloud Firmware Upgrade Is Disabled When an ITS Weekly Build Is Installed

When attempting to upgrade firmware using Cloud Firmware Update, some users may see the following warning:

“Please note that your new firmware download feature is disabled due to ITS installed.
Please contact local support to ensure the upgrade is applicable.”

This message indicates that the device is currently running an ITS Weekly Build.

Below, we explain what this means, why the upgrade is blocked, and how customers can safely move to an official release (FCS).

ITS (Issue Tracking System) Weekly Build

An ITS (Issue Tracking System) Weekly Build is a non-public, engineering-level firmware created by Zyxel R&D to address special or urgent cases.
Such builds may include:

• Fixes for specific customer-reported issues

• Temporary or experimental features

• Compatibility adjustments for unique environments

• Debug options not included in standard releases

ITS builds are usually identifiable by their firmware string, for example:
V5.41(ABTI.0)ITS-25WK10-20241014
V5.39(ABUI.1)ITS-25WK10-0424-250401225

Why Cloud Firmware Upgrade Is Blocked

Devices running an ITS firmware cannot download or install updates via:

• Cloud Firmware Update

• Nebula firmware management

• Automatic scheduling

This restriction is intentional and ensures:

1. No unintended downgrade
   ITS versions may be newer than public releases but are not release-certified.

2. Preservation of critical fixes
   The temporary fix included in the ITS firmware may not exist in official builds yet.

3. Stability and environment-specific behavior
   Automatic upgrades could remove custom features or workarounds required for the customer’s setup.

How Customers Can Identify Whether Their Issue Fix Is Included in an Official Release (FCS)

All official FCS releases and weekly updates include detailed Release Notes.
Customers should look for:

• Bug ID number (usually provided together with ITS firmware)

• Issue description

• Resolved items list

If the same Bug ID appears in the FCS release notes → the fix is included.

Example from release notes:

If your ITS version was created to fix this bug → you can safely upgrade to this FCS

How to Safely Upgrade from ITS Firmware to an Official FCS Version

Once confirmation is received that the fix is included in the FCS, customers can proceed.

Step 1 — Contact Zyxel Support to Unlock the Firmware

Support will:

• Validate that FCS is safe for your device

• Provide the correct firmware file or unlock the update path

Step 2 — Perform a Manual Firmware Upgrade

Because Cloud Firmware Update is blocked, customers must upgrade manually:

1. Download the FCS firmware file (provided by support).

2. Log in to the device locally (Web GUI).

3. Navigate to:
   Maintenance → File Manager → Firmware

4. Upload the FCS firmware file to Standby partition.

5. Reboot into the updated partition.

Step 3 — Verify the Running Partition Version

After reboot:

• The device should display the official firmware version (e.g. V5.41(ABTI.0))

• The ITS tag will disappear

• Cloud Firmware Update will be available again

What If the Fix Is Not Yet Included in an FCS Release?

If the fix is still only available in Weekly ITS firmware:

• You will need to continue using the ITS firmware until the next official release is published.

• Cloud Firmware updates remain disabled.

• Zyxel Support may provide an updated ITS build if required.

Summary