how do I change the language?

[RinyzNiko(守る)]

how to change the language from German to English in the game?

[schmusegewürzkatze621]

There does not seem to be a setting to change the application language after you’ve already chosen German on first start. I’ll try to find out where Zusi saves that setting and how to change it

[schmusegewürzkatze621]

It seems to be a registry entry. Looks like HKCU\Software\Zusi3\Einstellungen\Sprachverzeichnis needs to exist and be set to "English". Probably a setting that one could change easily through one of the other programs in the bundle if one were using the non-Steam Zusi 3 version. Alas, as it is, I don’t know whether uninstalling and reinstalling Zusi would work to reset the setting. You might need to go the regedit route.

[rob]

ZusiDateiverwaltung>Verwaltung>Generelle Zusi-Einstellungen>Sonstiges>Sprache>English.. No need to do a reinstall or editing the registry.

[schmusegewürzkatze621]

Ah, you see, but Zusi-Dateiverwaltung doesn’t work in Aerosoft Edition. Or at least it doesn’t work for me; maybe that’s a Proton thing?
Come to think of it, that’s probably the case, if you’re here and you’ve got the answer …
Apologies, then, and thank you for this information!

[rob]

Works for me: I do have the Aerosoft edition as well. Don't know what a Proton thing is.

[schmusegewürzkatze621]

Proton is a version of Wine and a component of Steam Play, which is integrated with Steam on macOS and Linux (including Steam Deck) to make it possible to run Windows-only games on those platforms. A lot of games run really well, but many others run into a few problems here and there. Including Zusi 3, unfortunately.

[denis.doyen]

J'ai essayé en lançant le programme Dateinverwaltung. Puis dans le menu "Verwaltung", j'ai sélectionné "Generelle Zusi-Einstellungen" et enfin "Sonstige" où il est possible de sélectionner la langue française. Comme après le changement lorsque j'ai lancé Zusi il était passé de l'Allemand (installé d'origine) à l'Anglais,

Ich habe es versucht, indem ich das Programm "Dateinverwaltung" gestartet habe. Dann habe ich im Menü "Verwaltung" "Generelle Zusi-Einstellungen" und schließlich "Sonstige" ausgewählt, wo man die deutsche Sprache auswählen kann. Wie nach der Änderung, als ich Zusi startete, war es von Deutsch (ursprünglich installiert) auf Englisch umgeschaltet.
Französisch funktioniert in der letzten Version (installiert im März 2023) nicht.

I tried this by starting the program Dateinverwaltung. Then in the menu "Verwaltung" I selected "Generelle Zusi-Einstellungen" and finally "Sonstige" where it is possible to select the French language. As after the change when I launched Zusi it had switched from German (originally installed) to English.
French does not work on the latest version (installed in March 2023)