The settings icon disappeared

[treebeard]

Code:

$ sudo apt install gnome-control-center
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
gnome-control-center : Depends: libgnome-desktop-3-19 (>= 3.33.4) but it is not installable
                        Recommends: gnome-user-docs but it is not going to be installed
                        Recommends: gnome-user-share but it is not going to be installed
                        Recommends: gkbd-capplet but it is not going to be installed
                        Recommends: system-config-printer-common (>= 1.4) but it is not going to be installed
                        Recommends: malcontent-gui but it is not going to be installed
                        Recommends: cracklib-runtime but it is not going to be installed
                        Recommends: realmd but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Ideas anyone?

I think that dependency list is out-dated.  Perhaps you didn't do the "apt update" to refresh package info? If that's not the problem try "apt --fix-broken install".

Edit 1: Are you on bullseye or bookworm?
Edit 2: Also do "apt-mark showhold" to see if you have any explicitly-held packages.