Can any one help me?
/etc/lighttpd/conf.d does not exist.
Debian Ubuntu?
docker raspberry pi 4b
Not sure.
That one used to be Debian based.
But I believe they transitioned to Alpine at some point.
Someone else surely knows 
You don't need help... There is nothing wrong.
/etc/lighttpd/conf.d only exists in Fedora/CentOS.
Pi-hole v5 image uses Debian 11 as base.
*** [ DIAGNOSING ]: Operating system
[i] Pi-hole Docker Container: 2024.07.0
[✓] Distro: Debian
[✓] Version: 11
The debug log will always show this message in docker.