Luci bug - config file not found

I installed openwrt on my range booster, then I installed luci.
it worked fine, then today I found this error while tring to open the webpage:

/usr/lib/lua/luci/dispatcher.lua:247: /etc/config/luci seems to be corrupt, unable to find section 'main' stack traceback: [C]: in function 'assert' /usr/lib/lua/luci/dispatcher.lua:247: in function 'dispatch' /usr/lib/lua/luci/dispatcher.lua:144: in function </usr/lib/lua/luci/dispatcher.lua:143>
after a reboot it stared working again.
before the reboot I sent some commands and I saved the log. I share the output of the hitted commands to allow you to better understand what's happening:


BusyBox v1.30.0 () built-in shell (ash)

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 OpenWrt SNAPSHOT, r8982-a54129d
 -----------------------------------------------------
root@OpenWrt:~#
root@OpenWrt:~# ls -la /etc/config/luci
-rw-r--r--    1 root     root           836 Jan  3 21:34 /etc/config/luci
root@OpenWrt:~# ls -la /usr/share/rpcd/acl.d/
drwxr-xr-x    2 root     root             0 Jan  3 21:34 .
drwxr-xr-x    3 root     root             0 Jan  3 21:24 ..
-rw-r--r--    1 root     root           159 Jan  3 21:24 luci-base.json
-rw-r--r--    1 root     root           179 Jan  2 14:47 unauthenticated.json
root@OpenWrt:~# ls -la /usr/share/acl.d/
drwxr-xr-x    1 root     root             0 Jan  3 21:34 .
drwxr-xr-x    1 root     root             0 Jan  3 21:24 ..
-rw-r--r--    1 root     root            50 Jan  3 21:24 dnsmasq_acl.json
-rw-r--r--    1 root     root            91 Jan  3 21:24 luci-base.json
root@OpenWrt:~#
root@OpenWrt:~#
root@OpenWrt:~# cat /etc/config/luci

config core 'main'
        option lang 'auto'
        option mediaurlbase '/luci-static/bootstrap'
        option resourcebase '/luci-static/resources'

config extern 'flash_keep'
        option uci '/etc/config/'
        option dropbear '/etc/dropbear/'
        option openvpn '/etc/openvpn/'
        option passwd '/etc/passwd'
        option opkg '/etc/opkg.conf'
        option firewall '/etc/firewall.user'
        option uploads '/lib/uci/upload/'

config internal 'languages'

config internal 'sauth'
        option sessionpath '/tmp/luci-sessions'
        option sessiontime '3600'

config internal 'ccache'
        option enable '1'

config internal 'themes'
        option Bootstrap '/luci-static/bootstrap'

config internal 'apply'
        option rollback '30'
        option holdoff '4'
        option timeout '5'
        option display '1.5'

config internal 'diag'
        option dns 'openwrt.org'
        option ping 'openwrt.org'
        option route 'openwrt.org'

root@OpenWrt:~#
root@OpenWrt:~# opkg list-installed
ath10k-firmware-qca988x-ct - 2018-10-10-d366b80d-1
base-files - 196-r8982-a54129d
busybox - 1.30.0-2
dnsmasq - 2.80-5
dropbear - 2017.75-9
firewall - 2019-01-02-70f8785b-2
fstools - 2018-12-28-af93f4b8-3
fwtool - 1
hostapd-common - 2018-12-02-c2c6c01b-1
ip6tables - 1.8.2-2
iptables - 1.8.2-2
iw - 4.14-1
iwinfo - 2018-12-25-dd508af4-1
jshn - 2018-07-25-c83a84af-2
jsonfilter - 2018-02-04-c7e938d6-1
kernel - 4.14.90-1-637dd8ee31c1d40b53577f651b6b9bab
kmod-ath - 4.14.90+4.19.7-1-1
kmod-ath10k-ct - 4.14.90+2018-12-20-118e16da-1
kmod-ath9k - 4.14.90+4.19.7-1-1
kmod-ath9k-common - 4.14.90+4.19.7-1-1
kmod-cfg80211 - 4.14.90+4.19.7-1-1
kmod-gpio-button-hotplug - 4.14.90-2
kmod-hwmon-core - 4.14.90-1
kmod-ip6tables - 4.14.90-1
kmod-ipt-conntrack - 4.14.90-1
kmod-ipt-core - 4.14.90-1
kmod-ipt-nat - 4.14.90-1
kmod-ipt-offload - 4.14.90-1
kmod-lib-crc-ccitt - 4.14.90-1
kmod-mac80211 - 4.14.90+4.19.7-1-1
kmod-nf-conntrack - 4.14.90-1
kmod-nf-conntrack6 - 4.14.90-1
kmod-nf-flow - 4.14.90-1
kmod-nf-ipt - 4.14.90-1
kmod-nf-ipt6 - 4.14.90-1
kmod-nf-nat - 4.14.90-1
kmod-nf-reject - 4.14.90-1
kmod-nf-reject6 - 4.14.90-1
kmod-ppp - 4.14.90-1
kmod-pppoe - 4.14.90-1
kmod-pppox - 4.14.90-1
kmod-slhc - 4.14.90-1
libblobmsg-json - 2018-07-25-c83a84af-2
libc - 1.1.20-1
libgcc - 7.4.0-1
libip4tc - 1.8.2-2
libip6tc - 1.8.2-2
libiwinfo - 2018-12-25-dd508af4-1
libiwinfo-lua - 2018-12-25-dd508af4-1
libjson-c - 0.12.1-2
libjson-script - 2018-07-25-c83a84af-2
liblua - 5.1.5-1
liblucihttp - 2018-05-18-cb119ded-1
liblucihttp-lua - 2018-05-18-cb119ded-1
libnl-tiny - 0.1-5
libpthread - 1.1.20-1
libubox - 2018-07-25-c83a84af-2
libubus - 2018-10-06-221ce7e7-1
libubus-lua - 2018-10-06-221ce7e7-1
libuci - 2018-08-11-4c8b4d6e-1
libuclient - 2018-11-24-3ba74ebc-1
libxtables - 1.8.2-2
logd - 2018-12-18-876c7f5b-1
lua - 5.1.5-1
luci - git-19.002.70367-c7776c8-1
luci-app-firewall - git-19.002.70367-c7776c8-1
luci-app-opkg - git-19.002.70367-c7776c8-1
luci-base - git-19.002.70367-c7776c8-1
luci-lib-ip - git-19.002.70367-c7776c8-1
luci-lib-jsonc - git-19.002.70367-c7776c8-1
luci-lib-nixio - git-19.002.70367-c7776c8-1
luci-mod-admin-full - git-19.002.70367-c7776c8-1
luci-mod-network - git-19.002.70367-c7776c8-1
luci-mod-status - git-19.002.70367-c7776c8-1
luci-mod-system - git-19.002.70367-c7776c8-1
luci-proto-ipv6 - git-19.002.70367-c7776c8-1
luci-proto-ppp - git-19.002.70367-c7776c8-1
luci-theme-bootstrap - git-19.002.70367-c7776c8-1
mtd - 23
netifd - 2018-12-16-2750ce2e-1
odhcp6c - 2018-07-14-67ae6a71-16
odhcpd-ipv6only - 2018-12-12-2d2a3b84-3
openwrt-keyring - 2018-05-18-103a32e9-1
opkg - 2017-12-07-3b417b9f-3
ppp - 2.4.7-14
ppp-mod-pppoe - 2.4.7-14
procd - 2018-11-23-d6673547-1
rpcd - 2018-11-28-3aa81d0d-1
rpcd-mod-rrdns - 20170710
swconfig - 12
uboot-envtools - 2018.03-3
ubox - 2018-12-18-876c7f5b-1
ubus - 2018-10-06-221ce7e7-1
ubusd - 2018-10-06-221ce7e7-1
uci - 2018-08-11-4c8b4d6e-1
uclient-fetch - 2018-11-24-3ba74ebc-1
uhttpd - 2018-11-28-cdfc902a-1
usign - 2015-07-04-ef641914-1
wireless-regdb - 2017-10-20-4343d359
wpad - 2018-12-02-c2c6c01b-1
root@OpenWrt:~#

an you help me to understand which is the problem?

I think "rpcd" fails sometimes, I have experienced the same issue, and could recover all the functionality by executing "/etc/init.d/rpcd restart". I would open a bug, but I cannot produce the failure on demand, or give more information.