Cannot upgrade Netgear WNDR3800

JoKr · March 13, 2023, 1:59pm

I have a Netgear WNDR3800, running OpenWrt 19.07.3. I want to upgrade it to the latest version (22.03.3).
SysUpgrade does not work. When I do:

Download any of these files:
https://downloads.openwrt.org/releases/22.03.3/targets/ath79/generic/openwrt-22.03.3-ath79-generic-netgear_wndr3800-squashfs-sysupgrade.bin
https://downloads.openwrt.org/releases/19.07.9/targets/ath79/generic/openwrt-19.07.9-ath79-generic-netgear_wndr3800-squashfs-sysupgrade.bin
In the Web UI go to System - Backup / Flash Firmware, select and upload a downloaded file I get the error:

cert_verify: cannot parse cert image check failed.

The uploaded image file does not contain a supported format. Make sure that you choose the generic image format for your platform.

How can I flash a new image?

frollic · March 13, 2023, 2:01pm

try going to 21.02 1st.

AndrewZ · March 13, 2023, 2:10pm

Use a bootloader.

JoKr · March 14, 2023, 9:29am

With the bootloader, do I use the sysupgrade image of the factory image?

AndrewZ · March 14, 2023, 9:36am

It should be the factory as I recall.
Please refer to https://openwrt.org/toh/netgear/wndr3800