最近在WMware中的ubuntu虚拟机遇到了循环登录问题，之前也遇到过好多次这个问题，在此记录一下这个坑。
BUG 重现
~/.Xsession-errors中的描述：
Xlib: extension "GLX" missing on display ":0".
openConnection: connect: No such file or directory
cannot connect to brltty at :0
upstart: gnome-session (Unity) main process (2254) terminated with status 1
upstart: unity-settings-daemon main process (2245) killed by TERM signal
upstart: Disconnected from notified D-Bus bus
upstart: logrotate main process (2082) killed by TERM signal
upstart: bamfdaemon main process (2173) killed by TERM signal
upstart: hud main process (2243) killed by TERM signal
upstart: indicator-messages main process (2293) killed by TERM signal
upstart: indicator-bluetooth main process (2294) killed by TERM signal
upstart: indicator-power main process (2295) killed by TERM signal
upstart: indicator-session main process (2300) killed by TERM signal
upstart: indicator-datetime main process (2296) killed by TERM signal
upstart: indicator-printers main process (2299) killed by TERM signal
upstart: unity-panel-service main process (2261) killed by TERM signal
upstart: indicator-keyboard main process (2297) killed by TERM signal
upstart: indicator-sound main process (2298) killed by TERM signal参考：ubuntu 手贱安装 nvidia-current nvidia-settings 导致无法启动桌面
解决办法
检查home目录下的.Xauthority文件：
ls -lanF .Xauthority应该显示一下内容：
-rw------- 1 1000 1000 49 Jun 21 20:24 .Xauthority中间两个最重要的是这个字段
1000 1000如果是其他的任何值，删去这个文件，然后重启
sudo rm ~/.Xauthority
sudo reboot参考：Thread: [SOLVED] Upgraded to 16.04 and can’t login
注意事项
- 如果安装了nvidia显卡驱动，将它卸载干净
sudo apt-get remove --purge nvidia-*- 使用 Ctrl+Alt+F1 或者Ctrl+Alt+F2进入文本模式进行操作
- 如果出现这个问题:”the system is running in low-graphics mode”，请移步 Ubuntu:The System is running in low-graphics mode 解决办法 或者
[ubuntu:the system is running in low-graphics mode的解决办法](http://www.th7.cn/system/lin/201708/225439.shtml)。