The GUI in Language Support is not a simple language *switcher*, but it's designed to also maintain the LANGUAGE priority list and gives you the opportunity to determine one or more fallback languages. Did you read Language Support Help?
So if the LANGUAGE items were: ar:de_DE:en_GB:en and you then dragged German to the top, it resulted in: de_DE:ar:en_GB:en Language Support isn't a mind reader, and didn't know that your intention was to get rid of Arabic completely. Since it was, you should have dragged the Arabic item below the English item. I installed Kaffeine, and found that it by default understands LANGUAGE (including German). Didn't see the app specific help menu, but it's probably there and overrides gettext. Personally I think it would have been better if Language Support had had a separate switcher for the first choice language, and another switcher for setting possible fallback languages. If you want you can file a wishlist bug with a suggestion along those lines. Closing this bug. ** Changed in: language-selector (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to language-selector in Ubuntu. https://bugs.launchpad.net/bugs/1653555 Title: Language settings stuck for KDE apps Status in language-selector package in Ubuntu: Invalid Bug description: On my Ubuntu 16.04 system, updates as of today, after switching my system language from german to arabic and later back using the unity- control-center, KDE apps got stuck to arabic language (all GUI elements right-to-left text in arabic language). All other apps open in german language. I now completely removed arabic from the language list (unchecked the box), but KDE apps still open using arabic language. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/language-selector/+bug/1653555/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp