As you say there is no configuration option to select the language version built-in Wikipedia search uses.
As @leocg suspects, Opera probably uses system locale to determine the Wikipedia language version: Neither Opera UI-language nor language preferences (→ Accept-Language: .. HTTP header) influence the Wiki search language, experiments prove.
I can suggest my Xeno Wikipedia (addons.opera, chrome web store, …) extension, though, which allows you to set an arbitrary default while being flexible to allow you to request other language versions occasionally. Maybe it suits your needs.
opera, your new project opera gx is more appreciated because your crew has done a great job in adding Whatsapp, Instagram, FB, Twitter, discord, etc...
but if you add Snapchat this browser will look a lot better
@leocg: I did not want to tinker with Opera's file locations myself, so yesterday I launched a new portable installation. I checked and the website works even after logging in. However, today on my daily installation of Opera, when I first visited the website, it worked, also after logging in, but as soon as i closed it and tried to open it a second time it's the same message again.
Now, in my daily Opera I have disabled all extension (except Opera Ad Blocker). To be sure, I restarted Opera, tried to view the page and it still doesn't work.
Apparently, the bug is actually on Opera's side, but it doesn't have to be there forever. Or there is some significant difference between the two installations, e.g. in the settings.
@cineatic said in "Das Upgrade erfordert zusätzliche Berechtigungen.":
Zum einen gab es nur eine Fehlermeldung, wenn ich den Befehl unter "Ausführen in" eingetragen habe. Egal ob mit oder ohne dem Pfad+Launcher.exe.
Wer sagt denn was von "Ausführen in"? Du sollst diese Zeile bei "Ziel" einfügen.
Der Entwicklermodus hat damit nichts zu tun bzw. das Update darin.