export QT_XKB_CONFIG_ROOT=/usr/share/X11/xkb

did not help to fix keyboard issue

cannot type in with the latest release

export QT_XKB_CONFIG_ROOT=/usr/share/X11/xkb
$ uname -a
E 4.15.0-36-generic #39~16.04.1-Ubuntu SMP Tue Sep 25 08:59:23 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux