Debian 12 has been released. As a result, the repositories for Debian 11 changed from „stable“ to „oldstable.“

If you try to run apt-get update on the server, you will encounter an error:

root@vps:/# apt-get update
Get:1 http://deb.debian.org/debian buster InRelease [122 kB]
Reading package lists... Done 
N: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Version' value from '10.9' to '10.10'
E: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Suite' value from 'stable' to 'oldstable'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

The change in the suite value must be explicitly confirmed. You can do this with a single command:

apt-get --allow-releaseinfo-change update

Using this command, we tell apt that the change has been accepted.

Now, you can use apt-get update, upgrade, and install as usual.