好的，我的问题开始于桌面上没有图标，我在终端中尝试了这些：
sudo apt-get update && sudo apt-get dist-upgrade
sudo apt-get install ubuntu-desktop
sudo apt-get -f install
gsettings set org.compiz.core:/org/compiz/profiles/unity/plugins/core/ active-plugins "['core', 'ccp', 'composite', 'opengl', 'place', 'snap', 'imgpng', 'resize', 'commands', 'compiztoolbox', 'move', 'mousepoll', 'grid', 'wall', 'vpswitch', 'unitymtgrabhandles', 'regex', 'copytex', 'session', 'animation', 'workarounds', 'expo','fade','scale','ezoom','unityshell']"
sudo rm /usr/lib/compiz/libprlcompiz_0_9_12_2.so
killall -9 prlcc
export DISPLAY=:0
setsid unity
sudo dconf reset -f /org/compiz/
export DISPLAY=:0
sudo apt-get upgrade
sudo apt-get update
我还将 nvidia 驱动程序从 340 更改为 361。我认为问题就出在这里。删除 nvidia 驱动程序后，我重新启动，但仍然无法登录。
这是我的 .xsession-errors 的内容：
openConnection: connect: No such file or directory
cannot connect to brltty at :0
upstart: unity7 main process (4088) killed by ABRT signal
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5530) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5540) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5550) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5560) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5570) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5583) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5594) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5604) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5614) terminated with status 1
upstart: unity7 main process ended, respawning
upstart: unity7 main process (5629) terminated with status 1
upstart: unity7 respawning too fast, stopped
upstart: bamfdaemon main process (3725) terminated with status 1
upstart: unity-panel-service main process (3861) terminated with status 1
upstart: indicator-keyboard main process (3904) terminated with status 1
upstart: indicator-printers main process (3910) terminated with status 1
upstart: unity-settings-daemon main process (3849) terminated with status 1
upstart: hud main process (3847) terminated with status 1
upstart: indicator-bluetooth main process (3900) killed by TERM signal
upstart: indicator-power main process (3902) killed by TERM signal
upstart: indicator-datetime main process (3903) killed by TERM signal
upstart: indicator-session main process (3911) killed by TERM signal
upstart: Disconnected from notified D-Bus bus
upstart: indicator-application main process (3926) killed by TERM signal
upstart: gnome-session (Unity) main process (3856) terminated with status 1
upstart: gpg-agent post-stop process (16030) killed by TERM signal
任何帮助都将非常有帮助。
谢谢