Ci4 system error localization not working

Because you need to load each language file for the language being used.

So you need a dropdown or whatever to pick the language and then load the language
they picked.

No, thats wrong.

CI4 automatically pick the local from the url (im using {local} in my routes) and if its a valid defined local then its set to the current local. as i said my apps views works fine with the de local. only the system views like this wont work.