por que esta linha aparece depois de instalar o kubuntu-desktop?

Question

Eu pensei em experimentar o kubuntu-desktop no meu xubuntu. Então eu instalei. Na reinicialização, uma linha branca aparece na minha tela. Eu removi todo o kubuntu-desktop que eu instalei anteriormente, mas a linha ainda permanece. Aqui está uma captura de tela. Como faço para removê-lo?

minha corrida atual ..........

android@android:~$ sudo python ps_mem.py
 Private  +   Shared  =  RAM used   Program

160.0 KiB +  42.5 KiB = 202.5 KiB   gnome-pty-helper
224.0 KiB +  31.0 KiB = 255.0 KiB   acpid
244.0 KiB +  28.0 KiB = 272.0 KiB   sh
284.0 KiB +  45.5 KiB = 329.5 KiB   agetty
332.0 KiB +  46.5 KiB = 378.5 KiB   irqbalance
316.0 KiB +  88.5 KiB = 404.5 KiB   cron
400.0 KiB +  87.0 KiB = 487.0 KiB   rtkit-daemon
408.0 KiB +  81.5 KiB = 489.5 KiB   systemd-timesyncd
432.0 KiB +  88.0 KiB = 520.0 KiB   dbus-launch
532.0 KiB +  20.5 KiB = 552.5 KiB   ssh-agent
232.0 KiB + 473.0 KiB = 705.0 KiB   bamfdaemon-dbus
580.0 KiB + 135.5 KiB = 715.5 KiB   gvfsd-metadata
604.0 KiB + 129.5 KiB = 733.5 KiB   xfconfd
688.0 KiB + 110.0 KiB = 798.0 KiB   dconf-service
700.0 KiB + 206.0 KiB = 906.0 KiB   gconfd-2
772.0 KiB + 137.5 KiB = 909.5 KiB   gvfs-mtp-volume-monitor
788.0 KiB + 124.5 KiB = 912.5 KiB   gvfs-goa-volume-monitor
848.0 KiB + 141.5 KiB = 989.5 KiB   dnsmasq
940.0 KiB +  69.5 KiB =   1.0 MiB   systemd-logind
376.0 KiB + 651.0 KiB =   1.0 MiB   avahi-daemon (2)
980.0 KiB + 230.0 KiB =   1.2 MiB   sudo
  1.0 MiB + 196.0 KiB =   1.2 MiB   gvfs-gphoto2-volume-monitor
  1.0 MiB + 312.0 KiB =   1.3 MiB   gvfsd-trash
  1.3 MiB +  90.0 KiB =   1.4 MiB   bluetoothd
  1.4 MiB + 173.0 KiB =   1.5 MiB   accounts-daemon
  1.2 MiB + 349.5 KiB =   1.5 MiB   thermald
  1.5 MiB +  79.5 KiB =   1.6 MiB   rsyslogd
  1.2 MiB + 450.5 KiB =   1.6 MiB   gvfs-afc-volume-monitor
  1.3 MiB + 478.5 KiB =   1.8 MiB   mount.ntfs (2)
  2.0 MiB +  39.0 KiB =   2.0 MiB   dhclient
  2.0 MiB + 130.0 KiB =   2.2 MiB   systemd-udevd
  1.6 MiB + 692.0 KiB =   2.2 MiB   (sd-pam)
  1.9 MiB + 452.5 KiB =   2.3 MiB   gvfs-udisks2-volume-monitor
  1.7 MiB + 621.0 KiB =   2.3 MiB   panel-4-systray
  1.7 MiB + 631.0 KiB =   2.4 MiB   cups-browsed
  2.0 MiB + 496.0 KiB =   2.5 MiB   bash
  2.3 MiB + 222.0 KiB =   2.5 MiB   polkitd
  2.0 MiB + 782.5 KiB =   2.8 MiB   panel-9-netload
  2.3 MiB + 509.5 KiB =   2.8 MiB   dbus-daemon (2)
  2.8 MiB +  97.5 KiB =   2.9 MiB   systemd-journald
  1.8 MiB +   1.1 MiB =   2.9 MiB   whoopsie
  2.9 MiB + 144.0 KiB =   3.0 MiB   gvfsd-fuse
  2.8 MiB + 295.5 KiB =   3.1 MiB   gvfsd
  2.3 MiB + 795.0 KiB =   3.1 MiB   lightdm (2)
  2.5 MiB + 669.0 KiB =   3.2 MiB   wpa_supplicant
  2.8 MiB + 720.5 KiB =   3.5 MiB   xfsettingsd
  3.6 MiB + 362.0 KiB =   3.9 MiB   ModemManager
  2.9 MiB +   1.2 MiB =   4.1 MiB   xfce4-power-manager (2)
  3.8 MiB + 510.0 KiB =   4.3 MiB   upowerd
  4.0 MiB + 341.0 KiB =   4.3 MiB   gnome-keyring-daemon
  3.7 MiB + 686.5 KiB =   4.4 MiB   xfce4-volumed
  2.5 MiB +   2.3 MiB =   4.8 MiB   systemd (2)
  3.8 MiB +   1.1 MiB =   4.9 MiB   polkit-gnome-authentication-agent-1
  4.2 MiB + 689.0 KiB =   4.9 MiB   panel-6-actions
  4.4 MiB + 722.5 KiB =   5.1 MiB   panel-5-power-m
  4.2 MiB +   1.0 MiB =   5.2 MiB   xfce4-panel
  5.2 MiB + 365.0 KiB =   5.6 MiB   udisksd
  4.9 MiB + 746.0 KiB =   5.6 MiB   pulseaudio
  4.3 MiB +   1.4 MiB =   5.7 MiB   light-locker
  5.2 MiB + 662.0 KiB =   5.9 MiB   xfce4-session
  5.1 MiB +   1.3 MiB =   6.3 MiB   panel-1-whisker
  6.1 MiB +   1.2 MiB =   7.3 MiB   xfce4-notifyd
  6.5 MiB +   1.0 MiB =   7.5 MiB   NetworkManager
  7.2 MiB +   1.8 MiB =   9.0 MiB   bamfdaemon
  7.8 MiB +   1.3 MiB =   9.1 MiB   xfce4-terminal
  6.8 MiB +   2.4 MiB =   9.1 MiB   panel-17-pulsea
  7.9 MiB +   1.5 MiB =   9.4 MiB   xfwm4
 11.1 MiB +  49.5 KiB =  11.1 MiB   snapd
 10.5 MiB +   2.5 MiB =  13.1 MiB   nm-applet
 12.8 MiB +   3.1 MiB =  15.9 MiB   plank
 17.6 MiB +   2.4 MiB =  20.0 MiB   Thunar
 18.7 MiB +   1.7 MiB =  20.4 MiB   xfdesktop
 25.4 MiB +   2.8 MiB =  28.2 MiB   gnome-system-monitor
 27.8 MiB +   1.6 MiB =  29.4 MiB   viewnior
 43.5 MiB +   4.4 MiB =  48.0 MiB   Xorg
 56.0 MiB +   4.2 MiB =  60.1 MiB   geary
731.0 MiB +  75.2 MiB = 806.2 MiB   opera (12)
---------------------------------
                          1.2 GiB
=================================

    

Answer 1

"show shadow under dock windows" no compositor é tudo o que eu tive que desabilitar.

gerenciador de janelas tweaks > compositor > mostre a sombra sob janelas da doca