On Fri, May 29, 2015 at 2:38 PM, Damjan Georgievski <gdamjan@xxxxxxxxx> wrote: >>>> error: unknown encoding UTF8: using iso88591 as fallback > ... > it seems for these apps it MUST be en_US.UTF-8 - that's the canonical > name of the encoding UTF-8 (with the dash). I don't think it is locale related, I've used both "en_US.utf8" and "en_US.UTF-8" in the past without issues. And encoding names are used in many other places. My guess is that you have somewhere a XML file with a wrong declaration <?xml version="1.0" encoding="UTF8"?> where the proper declaration would be: <?xml version="1.0" encoding="UTF-8"?> There are some configuration files both in /etc and $HOME that are read upon initialization of Gtk and Qt (see /etc/fonts/*), so I'd check those first: $ grep -ir 'encoding="utf8' /etc $ grep -ir 'encoding="utf8' ~/.config