Diagnosing and troubleshooting system log

Hi.

As a newbie here, I would like know how to diagnose my current errors on the system log.
(Here is it: https://drive.google.com/open?id=1YNMpzGLYQ1CJixSkkSdMUKGbcg6ZmLL1)
How to do that? What might I have been done something wrong?
Also, here is my installed packages list:

adblock	3.6.1-1
ath10k-firmware-qca988x	2018-12-16-211de167-1
base-files	192-r7258-5eb055306f
busybox	1.29.3-3
ca-bundle	20180409-3
dnsmasq-full	2.80-5
dropbear	2017.75-5
firewall	2018-12-06-14589c80-2
fstools	2018-04-16-e2436836-1
fwtool	1
hostapd-common	2018-05-21-62566bc2-7
ip6tables	1.6.2-1
ipset	7.1-1
iptables	1.6.2-1
iw	4.14-1
iwinfo	2018-07-24-94b1366d-1
jshn	2018-07-25-c83a84af-2
jsonfilter	2018-02-04-c7e938d6-1
kernel	4.9.120-1-adfb989a…
kmod-ath	4.9.120+2017-11-01-9
kmod-ath10k	4.9.120+2017-11-01-9
kmod-ath9k	4.9.120+2017-11-01-9
kmod-ath9k-common	4.9.120+2017-11-01-9
kmod-cfg80211	4.9.120+2017-11-01-9
kmod-gpio-button-hotplug	4.9.120-2
kmod-ip6tables	4.9.120-1
kmod-ipt-conntrack	4.9.120-1
kmod-ipt-core	4.9.120-1
kmod-ipt-ipset	4.9.120-1
kmod-ipt-nat	4.9.120-1
kmod-lib-crc-ccitt	4.9.120-1
kmod-mac80211	4.9.120+2017-11-01-9
kmod-nf-conntrack	4.9.120-1
kmod-nf-conntrack-netlink	4.9.120-1
kmod-nf-conntrack6	4.9.120-1
kmod-nf-ipt6	4.9.120-1
kmod-nf-nat	4.9.120-1
kmod-nf-reject	4.9.120-1
kmod-nf-reject6	4.9.120-1
kmod-nfnetlink	4.9.120-1
kmod-ppp	4.9.120-1
kmod-pppoe	4.9.120-1
kmod-pppox	4.9.120-1
kmod-slhc	4.9.120-1
kmod-tun	4.9.120-1
libc	1.1.19-1
libgcc	7.3.0-1
libgmp	6.1.2-1
libgnutls	3.6.5-1
libip4tc	1.6.2-1
libip6tc	1.6.2-1
libipset	7.1-1
libiwinfo	2018-07-24-94b1366d-1
libiwinfo-lua	2018-07-24-94b1366d-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
liblzo	2.10-1
libmbedtls	2.14.1-1
libmnl	1.0.4-1
libnetfilter-conntrack
libnettle	3.4.1-1
libnfnetlink	1.0.1-1
libnl-tiny	0.1-5
libopenssl	1.0.2p-1
libpcap	1.9.0-1
libpthread	1.1.19-1
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
libustream-mbedtls	2018-07-30-23a3f283-1
libxtables	1.6.2-1
logd	2018-12-18-876c7f5b-1
lua	5.1.5-1
luci	git-18.361.48411-39aa247-1
luci-app-adblock	git-18.361.48411-39aa247-1
luci-app-firewall	git-18.361.48411-39aa247-1
luci-app-openvpn	git-18.361.48411-39aa247-1
luci-app-opkg	git-18.361.48411-39aa247-1
luci-app-vpnbypass	git-18.361.48411-39aa247-4
luci-base	git-18.361.48411-39aa247-1
luci-lib-ip	git-18.361.48411-39aa247-1
luci-lib-jsonc	git-18.361.48411-39aa247-1
luci-lib-nixio	git-18.361.48411-39aa247-1
luci-mod-admin-full	git-18.361.48411-39aa247-1
luci-mod-network	git-18.361.48411-39aa247-1
luci-mod-status	git-18.361.48411-39aa247-1
luci-mod-system	git-18.361.48411-39aa247-1
luci-proto-ipv6	git-18.361.48411-39aa247-1
luci-proto-ppp	git-18.361.48411-39aa247-1
luci-theme-bootstrap	git-18.361.48411-39aa247-1
msmtp	1.8.1-1
mtd	23	~15.1 KB
netifd	2018-12-16-2750ce2e-1
odhcp6c	2018-07-14-67ae6a71-16
odhcpd-ipv6only	2018-12-12-2d2a3b84-3
openvpn-openssl	2.4.6-3
openwrt-keyring	2018-05-18-103a32e9-1
opkg	2017-12-07-3b417b9f-2
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
tcpdump	4.9.2-1
uboot-envtools	2018.03-1
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
vpnbypass	1.3.1-3
wireless-regdb	2017-10-20-4343d359
wpad-mini	2018-05-21-62566bc2-7

Thanks.

What errors?
To me the log looks rather normal.

Ok, I'm getting some anomalities esp. while clicking "Update lists" on Software section and can't configure msmtp correctly. Also, my traceroute esp. for airvpn.org and its DNS server (10.4.0.1) has too many timeout lines.
So, how to diagnose these totally?

Question: Shall all err flags be solved in some way?