USG 20 VPN

Jose

I have a USG 20 - Firmware 3.30 (BDQ.9) . I need to upgrade but it always say it's invalid. I've tried with 4.20 and 4.16 mas it's de same.
How can I upgrade the firmware?
Thanks

jasailafan

ZyWALL USG 20 and USG20-VPN are different models.

The latest firmware for USG 20 is 3.30 (BDQ.9). 

That's why it is impossible to upgrade USG 20 to 4.20.