How to change android system language if morelocale2 does not work I recently bought a chinese smartphone (SM-G3858) and there are only 3 languages available. English, Chinese and Korean. I tried to add another language (e.g. german) with the apps morelocale2, any locale, raygional, localeswitch, language picker widget... as already suggested in:

Is it posible to change the locale of my device? 

but the system language remains in the language I initially set up the phone with (English). Only the apps itself (e.g. the manually installed googleplay- so not system apps) are changed to german. The settings menu and the whole framework is still in English. No custom rom exists for that phone so thats out of the question. I tried via adb the command:

pm grant jp.co.c_lis.ccl.morelocale android.permission.CHANGE_CONFIGURATION

But that didnt work. I have root and run on 4.2.2 JB. Also tried to contact the dev of morelocale 2 but no answer. Also asked on xda, no answer. So I´m stuck. Im not interested in changing the keyboard language, cuz that works fine. I want to change the system language. I guess there is some kind of language lock on that phone. Now how can I override that lock? What do I need to change in order to have the whole system in the new locale language? And by the way. That phone works worldwide, so I guess that means that there is no region lock?

I could not find a thread with the exact same specifications mentioned. If one exists I would appreciate a link. Thank you
It's not that the locale is locked, it's just that it's only useful to change it to a language that's already on your phone. If the phone doesn't have a translation and other needed files for German, changing the locale to German won't have any effect. It's just like if you have a German phone and you install an app that's not translated into German: you'll get the app's default language.

You can only add a new system language by installing a custom ROM that supports that language, and as you've noticed, it's hard to find custom ROMs for Chinese phones.