I have a Xiaomi WiFi 3G router and installed long time ago OpenWrt
OpenWrt SNAPSHOT r6835-e495a05 / LuCI Master (git-18.125.76267-055b621) with Kernel 4.14.37
At these days, the upgrade seems to work with .tar files. Nowadays we have .bin files.
While trying to upgrade via
sysupgrade /tmp/openwrt-ramips-mt7621-xiaomi_mir3g-squashfs-sysupgrade.bin
I am getting errors
Invalid sysupgrade file.
Image check 'platform_check_image' failed.
any idea what I have to do?