我的 Ubuntu 14.04 在所有配置文件（包括 Guest 配置文件）下都陷入了登录循环。我确实通过另一台计算机的 ssh 获得了终端会话，并且可以Ctrl-Alt-F3到终端。我尝试了所有建议，重新拥有该.Xauthority文件并检查它是否.profiles没有损坏。我尝试重新安装光调制并重新配置并安装孕期但执行这些命令后出现了错误这页：
$ sudo apt-get purge lightdm; sudo apt-get install lightdm
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED
lightdm* ubuntu-desktop*
0 to upgrade, 0 to newly install, 2 to remove and 10 not to upgrade.
After this operation, 635 kB disk space will be freed.
Do you want to continue? [Y/n] Y
(Reading database ... 794245 files and directories currently installed.)
Removing ubuntu-desktop (1.325) ...
Removing lightdm (1.10.6-0ubuntu1) ...
Purging configuration files for lightdm (1.10.6-0ubuntu1) ...
Removing user `lightdm' ...
Warning: group `lightdm' has no more members.
userdel: user lightdm is currently used by process 1539
/usr/sbin/deluser: `/usr/sbin/userdel lightdm' returned error code 8. Exiting.
dpkg: error processing package lightdm (--purge):
subprocess installed post-removal script returned error exit status 1
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Errors were encountered while processing:
lightdm
E: Sub-process /usr/bin/dpkg returned an error code (1)
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed
lightdm
0 to upgrade, 1 to newly install, 0 to remove and 10 not to upgrade.
Need to get 0 B/108 kB of archives.
After this operation, 573 kB of additional disk space will be used.
Preconfiguring packages ...
Selecting previously unselected package lightdm.
(Reading database ... 794213 files and directories currently installed.)
Preparing to unpack .../lightdm_1.10.6-0ubuntu1_amd64.deb ...
Unpacking lightdm (1.10.6-0ubuntu1) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Processing triggers for ureadahead (0.100.0-16) ...
ureadahead will be reprofiled on next reboot
Setting up lightdm (1.10.6-0ubuntu1) ...
Processing triggers for ureadahead (0.100.0-16) ...
之后我需要选择光调制从列表中。它仍然卡在循环中。
和
$ sudo apt-get purge lightdm; sudo apt-get install gdm
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED
lightdm*
0 to upgrade, 0 to newly install, 1 to remove and 10 not to upgrade.
After this operation, 573 kB disk space will be freed.
Do you want to continue? [Y/n] Y
(Reading database ... 794242 files and directories currently installed.)
Removing lightdm (1.10.6-0ubuntu1) ...
Purging configuration files for lightdm (1.10.6-0ubuntu1) ...
Removing user `lightdm' ...
Warning: group `lightdm' has no more members.
userdel: user lightdm is currently used by process 1683
/usr/sbin/deluser: `/usr/sbin/userdel lightdm' returned error code 8. Exiting.
dpkg: error processing package lightdm (--purge):
subprocess installed post-removal script returned error exit status 1
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Errors were encountered while processing:
lightdm
E: Sub-process /usr/bin/dpkg returned an error code (1)
Reading package lists... Done
Building dependency tree
Reading state information... Done
gdm is already the newest version.
0 to upgrade, 0 to newly install, 0 to remove and 10 not to upgrade.
现在我什至无法获得 GUI 登录，它会传递到一个闪烁的屏幕显示Stopping System V runlevel compatibility。
尝试后sudo apt-get install lightdm ubuntu-desktop没有显示任何错误，但仍然陷入循环。
答案1
经过多次尝试，没有找到明确的解决方案，我设法通过 Unity Launcher 会话成功登录，到目前为止一切正常。我采取的步骤如下：
- 我使用 删除了专有显卡驱动程序
sudo apt-get remove fglrx*。重新启动后，这似乎没有改变任何东西。 - 我决定不仅删除该
.Xauthority文件，而且删除所有相关文件，sudo rm .Xauth*之后我可以登录，但没有统一启动器或状态栏等，只有背景和图标。 - 我尝试使用
sudo apt-get install --reinstall unity和重新安装 unity 和 ubuntu-desktopsudo apt-get install --reinstall ubuntu-desktop，但也没有改变任何东西。 - 我尝试使用基于以下图形方法重置 Unity：这链接，但似乎没有改变任何事情。
- 我通过这个相同的链接收到
dconf reset -f /org/compiz/一些消息说路径不正确，之后使用unity --reset-icons &disown似乎已经纠正了所有内容，我可以使用完整的统一启动器会话登录。
答案2
您最近是否安装了任何显卡驱动器？当我在 Ubuntu 15.10 上摆弄驱动程序时，我也遇到了此错误（登录循环）。
首先尝试卸载驱动程序。
我认为该命令适用于 AMD/ATI 驱动程序：
sudo aticonfig --uninstall
如果这不能解决您的问题，那么我很抱歉，您将必须重新安装:(