[ATP/FLEX] Why clicking “Upgrade Now” button on NCC server did not upgrade firmware continually?

Zyxel_Stanley Posts: 1,375  Zyxel Employee
First Anniversary 10 Comments Friend Collector First Answer
edited June 2023 in Maintenance

Due to Application Patrol signature parsing error, it may cause device unable to boot any more after rebooting the system. And also include system is unable to upgrade firmware from Nebula server no matter which App Patrol signature version was installed on your device.


If you clicked “Upgrade Now” button on Nebula server, but your device did not upgrade firmware continually. Please DO NOT Reboot Your System.

Please follow the steps to upgrade firmware by FTP from intranet.

Use FTP connect to your Firewall device LAN interface IP address, and then login by “admin” account.

You can find admin password by Nebula Configure > Site settings.

The steps fulfill for all of Nebula device except USG20-VPN and USG20W-VPN

If your device is USG20-VPN and USG20W-VPN, please wait for 5.21P1E1 firmware it will release before 31st Mar.


In the worst case, if your device is unable to boot up success.

You can follow the Steps to recover your system.