@marco.rieth I understand your frustration, we are here to help, so try to keep things positive please.
Passbolt use Gnupg for multiple reason, such as the authentication or data validation, as there is no other reliable tool to perform OpenPGP operations in PHP. During the setup since v2 it is required to provide a key that does not expire so that such maintenance is not required. Unfortunately that check was not present in version 1, so when you created a key during the server setup, there was no warning that you will run into this later.
Since 2.13 it is possible to update the server key and the users will be prompted to add a new one. It will look like this for the users:
There are several threads on the forum on how to do this. You need to update the expiration date in Gnupg, and export the key again from the keyring into the the config directory. There is another thread where it is described:
If you are still stuck, please provide information about what you did, what you tried, etc. so that we can continue to help you.