I am with YunoHost 4.0.7.1 (stable) on a Kimusfi Server.
My apps are update.
Since migration from Yunohost 3 to Yunohost 4, I have DNSMasq in a failed states and I can’t find why 
This is bellow what I have already tried without solving my problem. I was looking toward Bind9 because I already faced this issue when installing for the first time Yunohost of the Debian provided by Kimsufi.
I couldn’t find other possible issue in the forum.
admin@nos:~$ systemctl status dnsmasq.service
● dnsmasq.service - dnsmasq - A lightweight DHCP and caching DNS server
Loaded: loaded (/lib/systemd/system/dnsmasq.service; disabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Sun 2020-09-13 20:39:09 UTC; 1min 11s ago
admin@nos:~$ systemctl status bind9.service
● bind9.service
Loaded: masked (Reason: Unit bind9.service is masked.)
Active: inactive (dead)
admin@nos:~$ sudo systemctl unmask bind9.service
Removed /etc/systemd/system/bind9.service.
admin@nos:~$ systemctl status bind9.service
● bind9.service - LSB: Start and stop bind9
Loaded: loaded (/etc/init.d/bind9; generated)
Active: inactive (dead)
Docs: man:systemd-sysv-generator(8)
admin@nos:~$ sudo systemctl stop bind9.service
admin@nos:~$ systemctl status bind9.service
● bind9.service - LSB: Start and stop bind9
Loaded: loaded (/etc/init.d/bind9; generated)
Active: inactive (dead)
Docs: man:systemd-sysv-generator(8)
admin@nos:~$ sudo yunohost service regen-conf dnsmasq
Warning: ‘yunohost service regen-conf’ is deprecated! Please use ‘yunohost tools regen-conf’ instead.
Success! Configuration updated for ‘dnsmasq’
Warning: Job for dnsmasq.service failed because the control process exited with error code.
Warning: See “systemctl status dnsmasq.service” and “journalctl -xe” for details.
Error: Could not run script: /usr/share/yunohost/hooks/conf_regen/43-dnsmasq
dnsmasq:
applied:
/etc/resolv.dnsmasq.conf:
status: updated
pending:
admin@nos:~$ systemctl status dnsmasq.service
● dnsmasq.service - dnsmasq - A lightweight DHCP and caching DNS server
Loaded: loaded (/lib/systemd/system/dnsmasq.service; disabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Sun 2020-09-13 20:45:41 UTC; 19s ago
Process: 22915 ExecStartPre=/usr/sbin/dnsmasq --test (code=exited, status=0/SUCCESS)
Process: 22921 ExecStart=/etc/init.d/dnsmasq systemd-exec (code=exited, status=2)
admin@nos:~$ sudo systemctl start dnsmasq.service
Job for dnsmasq.service failed because the control process exited with error code.
See “systemctl status dnsmasq.service” and “journalctl -xe” for details.
admin@nos:~$ sudo apt-get remove bind9
Reading package lists… Done
Building dependency tree
Reading state information… Done
Package ‘bind9’ is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Could you help me t find where is the problem with my server ?