/usr/lib/lua/luci/dispatcher.lua:370: /etc/config/luci seems to be corrupt, unable to find section 'main'

Update to latest master and restore config from backup (~6 month old), got error: /usr/lib/lua/luci/dispatcher.lua:370: /etc/config/luci seems to be corrupt, unable to find section 'main'

#2885, #2799, #2231 - this is not first time.

Workaroud in this message: https://github.com/openwrt/luci/issues/2231#issuecomment-663915276 work for me: if I run rpcd from ssh then error gone.

I dig inside and found that in my backup /etc/config/rpcd

config rpcd
	option socket /var/run/ubus.sock
	option timeout 30

config login
	option username 'root'
	option password '$p$root'
	list read '*'
	list write '*'

This is from default config after reset:

config rpcd
	option socket /var/run/ubus/ubus.sock
	option timeout 30

config login
	option username 'root'
	option password '$p$root'
	list read '*'
	list write '*'

As you can see:

1. option socket is different.
2. if rpcd started without options - if uses proper path to socket, at least GUI works.

Why not remove option socket handling from /etc/config/rpcd and /etc/init.d/rpcd ?

[SmallAndSoft]

I have been watching real time graphs in luci and top over ssh. CPU eating luci subprocess quit and now I have this error. Restarting rpcd helped.

[Cadair]

I too got this after using the real time graphs.