The settings icon disappeared

[treebeard]

But I noticed that I get this message when updating, could that be the cause? Can it be fixed?

Code:

$ upd
Hit:1 http://deb.debian.org/debian bookworm InRelease
Get:2 http://repo.mobian.org bookworm InRelease [32.4 kB]
Err:2 http://repo.mobian.org bookworm InRelease 
  The following signatures were invalid: EXPKEYSIG 951D61F2BC232697 Mobian Project <admin@mobian-project.org>
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
All packages are up to date.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repo.mobian.org bookworm InRelease: The following signatures were invalid: EXPKEYSIG 951D61F2BC232697 Mobian Project <admin@mobian-project.org>
W: Failed to fetch http://repo.mobian.org/dists/bookworm/InRelease  The following signatures were invalid: EXPKEYSIG 951D61F2BC232697 Mobian Project <admin@mobian-project.org>
W: Some index files failed to download. They have been ignored, or old ones used instead.
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

Yep, that's the problem.  Your Debian repository is getting updated but the Mobian one isn't due to an authentication change.  There is a cure!