Dear Kedi (and other readers),

Last week I followed your suggestion of trying another (the latest) Debian distro. I made a slight modification, though: didn't pick Bullseye but the latest of Buster (deb10u5). And this helped.
Domoticz installed like a shine. Had some initial troubles in its GUI but ...

@Kedi,

I will give it a try and let you (all) know. Thx once again,

Steijn

Dear Kedi (and other readers),

Good suggestion indeed: "sudo apt-get install git" eventually gives me:

Err:1 http://raspbian<dot>raspberrypi<dot>org/raspbian buster/main armhf libcurl3-gnutls armhf 7<dot>64<dot>0-4+deb10u1
404 Not Found [IP: 93<dot>93<dot>128<dot>193 80]
Err:2 http://raspbian ...

Dear Kedi,

Sorry for my late response. I have many things on my hands and was just checking my e-mail regularly in the meantime. But I saw no replies to my problem/post.
However, when I went online to actually read back my own post I saw your reply. And that, by default, in my forum profile, no ...

Hello, dear forum readers, I just installed Raspbian on my RPi and tried to install Domoticz on top of that. It won't:

pi@Domotix2:/etc$ sudo bash -c "$(curl -sSfL https://install.domoticz.com)"
:::
:::
::: You are root.
::: Verifying free disk space...
:::
::: apt-get update has not been run ...