16.04 → get back to normal situation ( with accented letters ) thanks to Bertrand0 here https://forum.ubuntu-fr.org/viewtopic.php?pid=21586183#p21586183 which also confirms BleachBit is to blame.
sudo aptitude reinstall apt chromium-browser chromium-browser-l10n cups- common dconf-editor debconf-i18n dpkg e2fsprogs example-content firefox firefox-locale-fr fwupdate gimp-data gimp-plugin-registry gksu gnome- icon-theme gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly iso-codes language-pack-fr language-pack-fr-base language-pack-gnome-fr language- pack-gnome-fr-base language-selector-common libapt-inst2.0 libapt-pkg5.0 libc-bin libgimp2.0 libgksu2-0 libgom-1.0-common liboxideqtcore0 libqt4-script libstdc++-5-dev libx11-data libzvbi-common locales menu pavucontrol qtcore4-l10n qttranslations5-l10n radiotray synaptic unity- lens-applications unity-lens-files unity-tweak-tool update-notifier- common vlc-data xdg-user-dirs xkb-data-i18n xscreensaver I'm still struggling with 14.04… -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1599516 Title: No accented letters in window title bars, dash and hud. To manage notifications about this bug go to: https://bugs.launchpad.net/bleachbit/+bug/1599516/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
