manpath: can’t set the locale; make sure $LC_* and $LANG are correct

Try this https://gist.github.com/SimonSun1988/2ef7db45e46b889783647d941ec15e4d

sudo locale-gen "en_US.UTF-8"
sudo dpkg-reconfigure locales

and in file /etc/default/locale add line LC_ALL="en_US.UTF-8" and relogin to your server.