I upgraded from Ubuntu 14.04 LTS to 16.04 LTS. I had manually installed LibreOffice 5.1 on Ubuntu 14.04 and there was no problem. As part of the upgrade process LibreOffice 18.104.22.168 was re-installed automatically. Now when I see file properties, it displays non printable characters in parts of the General tab of Properties. This is also happening in tabs of Tools -> Customize and messages displayed by Librecalc. The language settings are set to English. How can this be rectified.