Unable to change the language

I am not able to Change the Default language Setting from English to German. If I click once onto the language Options the screen get into a Freeze mode and the only way to continue is to press Crtl +Alt + Del to stop Mincraft. If I start the Program again the language is set to one of the first Options. I tried it now several times I am even not able to Change the Settings back to English, even if I  deinstall and install Minecraft again.

Please fix it asap because with a Russian language I am not able to Play and more.