Yes, I solved my problem. Starting from a new installation was much more effective.

I just hope I haven't forgotten any files to back up.

Sorry, I don't speak English, my messages (in English) are translations from French to English by ChatGPT.

It's working now.
I started with a "fresh" server and, before launching it for the first time, I modified the /mods/mod-list.json file to set the new mods to false.

Then I copied the following files:

- data/server-settings.json
- saves/gamesave.zip
- player-data.json

I hope I haven't forgotten ...

I had set up a new server to try and understand how it works.
I noticed different behavior—when I modified the /mods/mod-list.json file and restarted the server, it automatically turned the "false" values back to "true."

With your question, I realized that the map might have an influence.
So, I ...

No, the save file comes from version 1.1.110, so it should be without space-age mods.

Hello,

We're playing on a server, and today the game clients were updated via Steam to version 2.0.7.
It's now impossible to connect to the server running version 1.1.110, so I updated the server to 2.0.7.

However, when I try to connect to the server, it's asking for three mods (the space-age mods ...