Не удалось подключиться к Миру. Не удалось подключиться к сокету сервера: Разрешение запрещено

Примерно через 10 секунд после того, как я войду в систему как пользователь xx, он выйдет на экран входа в систему. Затем я вхожу в систему как root, и su xx, и zsh показывают мне, что

zsh: locking failed for /home/xx/.zsh_history: permission denied: reading anyway

Затем я набираю следующий код

➜  Desktop gedit test.c 
No protocol specified
Failed to connect to Mir: Failed to connect to server socket: Permission denied
Unable to init server: Could not connect: Connection refused

(gedit:3296): Gtk-WARNING **: cannot open display: :0
➜  Desktop echo $DISPLAY
:0
➜  Desktop ./Link\ to\ qtcreator 
QStandardPaths: wrong ownership on runtime directory /run/user/999, 999 instead of 1000
No protocol specified
qt.qpa.screen: QXcbConnection: Could not connect to display :0
Could not connect to any X display.

➜  cat .xsession-errors  
openConnection: connect: No such file or directory
cannot connect to brltty at :0
upstart: logrotate main process (1813) killed by TERM signal
upstart: window-stack-bridge main process (1837) killed by HUP signal
upstart: gnome-session (Unity) pre-stop process (2381) killed by TERM signal
upstart: bamfdaemon main process (1919) killed by TERM signal
upstart: hud main process (1973) killed by HUP signal
upstart: unity-settings-daemon main process (1975) killed by HUP signal
upstart: at-spi2-registryd main process (1980) killed by HUP signal
upstart: gnome-session (Unity) main process (1982) killed by TERM signal
upstart: unity-panel-service main process (1989) killed by HUP signal
upstart: indicator-messages main process (2039) killed by HUP signal
upstart: indicator-bluetooth main process (2040) killed by TERM signal
upstart: indicator-power main process (2041) killed by TERM signal
upstart: indicator-datetime main process (2045) killed by TERM signal
upstart: indicator-keyboard main process (2048) killed by HUP signal
upstart: indicator-sound main process (2050) killed by HUP signal
upstart: indicator-printers main process (2052) killed by TERM signal
upstart: indicator-session main process (2053) killed by TERM signal
upstart: indicator-application main process (2071) killed by TERM signal
upstart: indicator-application pre-stop process (2375) killed by TERM signal
upstart: unity7 main process (2156) terminated with status 1
upstart: Disconnected from notified D-Bus bus

Возможно, проблема в каком-то профиле, но я не знаю, какой файл редактировать. Что мне теперь делать?