Problem:
When you try to open your OpenWRT Web UI, you see an error message like
/usr/lib/lua/luci/dispatcher.lua:427: /etc/config/luci seems to be corrupt, unable to find section 'main'
Solution:
In my case, the issue was a bad rpcd configuration which I restored from an older OpenWRT version that contained the config line
option socket /var/run/ubus.sock
instead of the correct
option socket /var/run/ubus/ubus.sock
You can replace your rpcd config by the default by running the following command over SSH:
cp /rom/etc/config/rpcd /etc/config/rpcd
and then
reboot