USG 20W upgrade old firmware
I have a Zyxel USG 20W with firmware 3.30(BDR.7) and would like to upgrade it to the latest version. I can only find firmware for the model USG 20W-VPN firmware version 4.35(ABAR.0).
I attempted the upgrade to the device but received and error saying the firmware was incompatible. I am not sure if this is because my device is a different model (note that -VPN is missing in the model number on my device) or because the jump from 3.30 to 4.35 is to big. Or both. I may also be a separate issue altogether.
Any guidance on next best steps would be appreciated.