I run into the same issue today. It's not strictly MongoDB related. It's locale/language related. Somehow the language on your computer is not defined correctly. I managed to fix my problem by typing:
sudo locale-gen en_US en_US.UTF-8
sudo locale-gen xx_XX xx_XX.UTF-8
sudo dpkg-reconfigure locales
These commands are to generate and configure the needed locales. After those steps everything should work as expected.