running 16.04 since its official release. Up to date. Since few days I have a problem with accented letters :
- in dash if I type « démarrage » on keayboard I only get «dmarrage» in the dash,
- same behavior in HUD,
- in windows title bars accented letters are replaced with kind of squares.
For (3) letters are correct once window is maximised that is to say when title bar is in the top panel. I've found other discussion here about that, with neither explanation nor fix : Accented characters not rendering correctly on title bar in Ubuntu 14.04 or Weird "Box-like" Characters Showing up in Title Bar of Windows
Here you may find illustrations of my situation and what has been checked so far about locales and other language settings ( in french ) https://forum.ubuntu-fr.org/viewtopic.php?pid=21551698#p21551698
And last here is reported bug on Launchpad https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1599516