我刚刚进行了更新，现在，每当我的屏幕锁定时（无论是手动还是超时后自动锁定），我都会输入密码，它会解锁一小会儿，但所有窗口边框都消失了，好像窗口管理器死了一样，大约 2 秒钟后它又会锁定。之后我无法返回系统。当我运行命令时unity，它会抱怨无法连接到org.gnome.ScreenSaver，然后出现段错误。
我该怎么办？如果没有解决方案，我该如何恢复更新？
/var/log/apt/history.log：
Start-Date: 2018-03-04 11:53:25
Commandline: aptdaemon role='role-commit-packages' sender=':1.95'
Install: linux-headers-4.4.0-116:amd64 (4.4.0-116.140, automatic), linux-image-extra-4.4.0-116-generic:amd64 (4.4.0-116.140, automatic), linux-headers-4.4.0-116-generic:amd64 (4.4.0-116.140, automatic), linux-image-4.4.0-116-generic:amd64 (4.4.0-116.140, automatic)
Upgrade: libreoffice-style-breeze:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libreoffice-math:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), gnome-accessibility-themes:amd64 (3.18.0-2ubuntu1, 3.18.0-2ubuntu2), libaudit-common:amd64 (1:2.4.5-1ubuntu2, 1:2.4.5-1ubuntu2.1), linux-headers-generic:amd64 (4.4.0.112.118, 4.4.0.116.122), linux-libc-dev:amd64 (4.4.0-112.135, 4.4.0-116.140), bamfdaemon:amd64 (0.5.3~bzr0+16.04.20160824-0ubuntu1, 0.5.3~bzr0+16.04.20180209-0ubuntu1), libpulsedsp:amd64 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), grub-common:amd64 (2.02~beta2-36ubuntu3.16, 2.02~beta2-36ubuntu3.17), linux-image-generic:amd64 (4.4.0.112.118, 4.4.0.116.122), pulseaudio:amd64 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), libreoffice-core:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libreoffice-gtk:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libsnmp-base:amd64 (5.7.3+dfsg-1ubuntu4, 5.7.3+dfsg-1ubuntu4.1), libreoffice-style-human:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), python-apt-common:amd64 (1.1.0~beta1build1, 1.1.0~beta1ubuntu0.16.04.1), grub2-common:amd64 (2.02~beta2-36ubuntu3.16, 2.02~beta2-36ubuntu3.17), isc-dhcp-common:amd64 (4.3.3-5ubuntu12.7, 4.3.3-5ubuntu12.9), libdfu1:amd64 (0.7.0-0ubuntu4.3, 0.8.3-0ubuntu2), grub-pc:amd64 (2.02~beta2-36ubuntu3.16, 2.02~beta2-36ubuntu3.17), python3-uno:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libreoffice-style-galaxy:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libreoffice-base-core:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libbamf3-2:amd64 (0.5.3~bzr0+16.04.20160824-0ubuntu1, 0.5.3~bzr0+16.04.20180209-0ubuntu1), grub-pc-bin:amd64 (2.02~beta2-36ubuntu3.16, 2.02~beta2-36ubuntu3.17), ntpdate:amd64 (1:4.2.8p4+dfsg-3ubuntu5.7, 1:4.2.8p4+dfsg-3ubuntu5.8), libreoffice-ogltrans:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libreoffice-impress:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libsnmp30:amd64 (5.7.3+dfsg-1ubuntu4, 5.7.3+dfsg-1ubuntu4.1), ubuntu-drivers-common:amd64 (1:0.4.17.3, 1:0.4.17.7), python3-distupgrade:amd64 (1:16.04.23, 1:16.04.24), libpulse0:amd64 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), libpulse0:i386 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), ubuntu-release-upgrader-core:amd64 (1:16.04.23, 1:16.04.24), libpulse-mainloop-glib0:amd64 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), libpulse-dev:amd64 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), ure:amd64 (5.1.6~rc2-0ubuntu1~xenial2, 5.1.6~rc2-0ubuntu1~xenial3), libreoffice-writer:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), python-apt:amd64 (1.1.0~beta1build1, 1.1.0~beta1ubuntu0.16.04.1), libreoffice-common:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libfwupd1:amd64 (0.7.0-0ubuntu4.3, 0.8.3-0ubuntu2), pulseaudio-module-x11:amd64 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), ubuntu-release-upgrader-gtk:amd64 (1:16.04.23, 1:16.04.24), fonts-opensymbol:amd64 (2:102.7+LibO5.1.6~rc2-0ubuntu1~xenial2, 2:102.7+LibO5.1.6~rc2-0ubuntu1~xenial3), fwupd:amd64 (0.7.0-0ubuntu4.3, 0.8.3-0ubuntu2), pulseaudio-module-bluetooth:amd64 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), libreoffice-pdfimport:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), uno-libs3:amd64 (5.1.6~rc2-0ubuntu1~xenial2, 5.1.6~rc2-0ubuntu1~xenial3), linux-firmware:amd64 (1.157.16, 1.157.17), libreoffice-gnome:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), libreoffice-calc:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), pulseaudio-utils:amd64 (1:8.0-0ubuntu3.7, 1:8.0-0ubuntu3.8), isc-dhcp-client:amd64 (4.3.3-5ubuntu12.7, 4.3.3-5ubuntu12.9), linux-generic:amd64 (4.4.0.112.118, 4.4.0.116.122), libaudit1:amd64 (1:2.4.5-1ubuntu2, 1:2.4.5-1ubuntu2.1), sensible-utils:amd64 (0.0.9, 0.0.9ubuntu0.16.04.1), libreoffice-draw:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), python3-apt:amd64 (1.1.0~beta1build1, 1.1.0~beta1ubuntu0.16.04.1), libreoffice-avmedia-backend-gstreamer:amd64 (1:5.1.6~rc2-0ubuntu1~xenial2, 1:5.1.6~rc2-0ubuntu1~xenial3), base-files:amd64 (9.4ubuntu4.5, 9.4ubuntu4.6)
End-Date: 2018-03-04 12:18:19
~/.xsession-errors（错误含义为“没有这样的文件或目录”）：
openConnection: connect: Nie ma takiego pliku ani katalogu
cannot connect to brltty at :0
lightdm.log（除了最开始的几行，因为超出了字符数限制）：
[+0.23s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.23s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+15.04s] DEBUG: Got signal 10 from process 1070
[+15.04s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+15.04s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+15.04s] DEBUG: Launching process 1142: /sbin/prime-offload
[+15.05s] DEBUG: Process 1142 exited with return value 0
[+15.05s] DEBUG: Seat seat0: Exit status of /sbin/prime-offload: 0
[+15.05s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+15.05s] DEBUG: Session pid=1148: Started with service 'lightdm-greeter', username 'lightdm'
[+15.08s] DEBUG: Session pid=1148: Authentication complete with return value 0: Success
[+15.08s] DEBUG: Seat seat0: Session authenticated, running command
[+15.08s] DEBUG: Session pid=1148: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter
[+15.08s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+15.08s] DEBUG: Session pid=1148: Logging to /var/log/lightdm/seat0-greeter.log
[+15.24s] DEBUG: Activating VT 7
[+15.25s] DEBUG: Activating login1 session c1
[+15.25s] DEBUG: Seat seat0 changes active session to c1
[+15.25s] DEBUG: Session c1 is already active
[+16.83s] DEBUG: Greeter connected version=1.18.3 resettable=false
[+20.72s] DEBUG: Greeter start authentication for mariusz
[+20.72s] DEBUG: Session pid=1648: Started with service 'lightdm', username 'mariusz'
[+20.72s] DEBUG: Session pid=1648: Got 1 message(s) from PAM
[+20.72s] DEBUG: Prompt greeter with 1 message(s)
[+21.06s] DEBUG: User /org/freedesktop/Accounts/User112 added
[+31.71s] DEBUG: Continue authentication
[+31.72s] DEBUG: Session pid=1648: Authentication complete with return value 0: Success
[+31.72s] DEBUG: Authenticate result for user mariusz: Success
[+31.72s] DEBUG: User mariusz authorized
[+31.73s] DEBUG: Greeter requests session ubuntu
[+31.73s] DEBUG: Seat seat0: Stopping greeter; display server will be re-used for user session
[+31.73s] DEBUG: Session pid=1148: Sending SIGTERM
[+31.77s] DEBUG: Greeter closed communication channel
[+31.77s] DEBUG: Session pid=1148: Exited with return value 0
[+31.77s] DEBUG: Seat seat0: Session stopped
[+31.77s] DEBUG: Seat seat0: Greeter stopped, running session
[+31.77s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+31.78s] DEBUG: Session pid=1648: Running command /usr/sbin/lightdm-session gnome-session --session=ubuntu
[+31.78s] DEBUG: Creating shared data directory /var/lib/lightdm-data/mariusz
[+31.78s] DEBUG: Session pid=1648: Logging to .xsession-errors
[+31.82s] DEBUG: Activating VT 7
[+31.82s] DEBUG: Activating login1 session c2
[+31.82s] DEBUG: Seat seat0 changes active session to c2
[+31.82s] DEBUG: Session c2 is already active
[+78.50s] DEBUG: Seat seat0 changes active session to
[+83.48s] DEBUG: Seat seat0 changes active session to 1
[+88.03s] DEBUG: Session pid=1648: Terminated with signal 1
[+88.03s] DEBUG: Seat seat0: Session stopped
[+88.03s] DEBUG: Seat seat0: Stopping display server, no sessions require it
[+88.03s] DEBUG: Sending signal 15 to process 1070
[+88.06s] DEBUG: Got signal 15 from process 1
[+88.06s] DEBUG: Caught Terminated signal, shutting down
[+88.06s] DEBUG: Stopping display manager
[+88.06s] DEBUG: Seat seat0: Stopping
[+88.24s] DEBUG: Process 1070 exited with return value 0
[+88.24s] DEBUG: DisplayServer x-0: X server stopped
[+88.24s] DEBUG: Releasing VT 7
[+88.24s] DEBUG: DisplayServer x-0: Removing X server authority /var/run/lightdm/root/:0
[+88.24s] DEBUG: Seat seat0: Display server stopped
[+88.24s] DEBUG: Launching process 2866: /sbin/prime-switch
[+88.40s] DEBUG: Process 2866 exited with return value 0
[+88.40s] DEBUG: Seat seat0: Exit status of /sbin/prime-switch: 0
[+88.40s] DEBUG: Seat seat0: Stopped
[+88.40s] DEBUG: Display manager stopped
[+88.40s] DEBUG: Stopping daemon
[+88.40s] DEBUG: Exiting with return value 0
[+0.09s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.12s] DEBUG: Starting Light Display Manager 1.18.3, UID=0 PID=1113
[+0.12s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-disable-log-backup.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/90-nvidia.conf
[+0.12s] DEBUG: [SeatDefaults] is now called [Seat:*], please update this configuration
[+0.12s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.12s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.12s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.12s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.12s] DEBUG: Registered seat module xlocal
[+0.12s] DEBUG: Registered seat module xremote
[+0.12s] DEBUG: Registered seat module unity
[+0.12s] DEBUG: Monitoring logind for seats
[+0.12s] DEBUG: New seat added from logind: seat0
[+0.12s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.12s] DEBUG: Seat seat0: Starting
[+0.12s] DEBUG: Seat seat0: Creating greeter session
[+0.21s] DEBUG: Seat seat0: Creating display server of type x
[+0.21s] DEBUG: Quitting Plymouth
[+0.23s] DEBUG: Using VT 7
[+0.23s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.23s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.23s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.23s] DEBUG: DisplayServer x-0: Launching X Server
[+0.23s] DEBUG: Launching process 1126: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.23s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.23s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.23s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.26s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.26s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+13.87s] DEBUG: Got signal 10 from process 1126
[+13.87s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+13.87s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+13.87s] DEBUG: Launching process 1268: /sbin/prime-offload
[+13.87s] DEBUG: Process 1268 exited with return value 0
[+13.87s] DEBUG: Seat seat0: Exit status of /sbin/prime-offload: 0
[+13.87s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+13.87s] DEBUG: Session pid=1274: Started with service 'lightdm-greeter', username 'lightdm'
[+13.90s] DEBUG: Session pid=1274: Authentication complete with return value 0: Success
[+13.90s] DEBUG: Seat seat0: Session authenticated, running command
[+13.90s] DEBUG: Session pid=1274: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter
[+13.90s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+13.90s] DEBUG: Session pid=1274: Logging to /var/log/lightdm/seat0-greeter.log
[+14.07s] DEBUG: Activating VT 7
[+14.07s] DEBUG: Activating login1 session c1
[+14.07s] DEBUG: Seat seat0 changes active session to c1
[+14.07s] DEBUG: Session c1 is already active
[+15.12s] DEBUG: Greeter connected version=1.18.3 resettable=false
[+18.39s] DEBUG: Greeter start authentication for mariusz
[+18.39s] DEBUG: Session pid=1429: Started with service 'lightdm', username 'mariusz'
[+18.40s] DEBUG: Session pid=1429: Got 1 message(s) from PAM
[+18.40s] DEBUG: Prompt greeter with 1 message(s)
[+19.34s] DEBUG: User /org/freedesktop/Accounts/User112 added
[+40.62s] DEBUG: Continue authentication
[+40.63s] DEBUG: Session pid=1429: Authentication complete with return value 0: Success
[+40.63s] DEBUG: Authenticate result for user mariusz: Success
[+40.63s] DEBUG: User mariusz authorized
[+40.64s] DEBUG: Greeter requests session ubuntu
[+40.64s] DEBUG: Seat seat0: Stopping greeter; display server will be re-used for user session
[+40.64s] DEBUG: Session pid=1274: Sending SIGTERM
[+40.74s] DEBUG: Greeter closed communication channel
[+40.74s] DEBUG: Session pid=1274: Exited with return value 0
[+40.74s] DEBUG: Seat seat0: Session stopped
[+40.74s] DEBUG: Seat seat0: Greeter stopped, running session
[+40.74s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+40.74s] DEBUG: Session pid=1429: Running command /usr/sbin/lightdm-session gnome-session --session=ubuntu
[+40.74s] DEBUG: Creating shared data directory /var/lib/lightdm-data/mariusz
[+40.74s] DEBUG: Session pid=1429: Logging to .xsession-errors
[+40.78s] DEBUG: Activating VT 7
[+40.78s] DEBUG: Activating login1 session c2
[+40.78s] DEBUG: Seat seat0 changes active session to c2
[+40.78s] DEBUG: Session c2 is already active
[+192.55s] DEBUG: Seat seat0 changes active session to
[+206.14s] DEBUG: Seat seat0 changes active session to 1
[+213.16s] DEBUG: Got signal 15 from process 1
[+213.16s] DEBUG: Caught Terminated signal, shutting down
[+213.16s] DEBUG: Stopping display manager
[+213.16s] DEBUG: Seat seat0: Stopping
[+213.16s] DEBUG: Seat seat0: Stopping display server
[+213.16s] DEBUG: Sending signal 15 to process 1126
[+213.16s] DEBUG: Seat seat0: Stopping session
[+213.16s] DEBUG: Session pid=1429: Sending SIGTERM
[+213.24s] DEBUG: Session pid=1429: Terminated with signal 1
[+213.24s] DEBUG: Seat seat0: Session stopped
[+213.39s] DEBUG: Seat seat0 changes active session to
[+213.39s] CRITICAL: session_get_login1_session_id: assertion 'session != NULL' failed
[+213.42s] DEBUG: Process 1126 exited with return value 0
[+213.42s] DEBUG: DisplayServer x-0: X server stopped
[+213.42s] DEBUG: Releasing VT 7
[+213.42s] DEBUG: DisplayServer x-0: Removing X server authority /var/run/lightdm/root/:0
[+213.42s] DEBUG: Seat seat0: Display server stopped
[+213.42s] DEBUG: Launching process 3358: /sbin/prime-switch
[+213.64s] DEBUG: Process 3358 exited with return value 0
[+213.64s] DEBUG: Seat seat0: Exit status of /sbin/prime-switch: 0
[+213.64s] DEBUG: Seat seat0: Stopped
[+213.64s] DEBUG: Display manager stopped
[+213.64s] DEBUG: Stopping daemon
[+213.65s] DEBUG: Exiting with return value 0
[+0.05s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.12s] DEBUG: Starting Light Display Manager 1.18.3, UID=0 PID=1092
[+0.12s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-disable-log-backup.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
[+0.12s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/90-nvidia.conf
[+0.12s] DEBUG: [SeatDefaults] is now called [Seat:*], please update this configuration
[+0.12s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.12s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.12s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.12s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.12s] DEBUG: Registered seat module xlocal
[+0.12s] DEBUG: Registered seat module xremote
[+0.12s] DEBUG: Registered seat module unity
[+0.12s] DEBUG: Monitoring logind for seats
[+0.12s] DEBUG: New seat added from logind: seat0
[+0.12s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.12s] DEBUG: Seat seat0: Starting
[+0.12s] DEBUG: Seat seat0: Creating greeter session
[+0.17s] DEBUG: Seat seat0: Creating display server of type x
[+0.17s] DEBUG: Quitting Plymouth
[+0.18s] DEBUG: Using VT 7
[+0.18s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.18s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.18s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.18s] DEBUG: DisplayServer x-0: Launching X Server
[+0.18s] DEBUG: Launching process 1103: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.18s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.18s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.18s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.21s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.21s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+14.74s] DEBUG: Got signal 10 from process 1103
[+14.74s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+14.74s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+14.74s] DEBUG: Launching process 1455: /sbin/prime-offload
[+14.74s] DEBUG: Process 1455 exited with return value 0
[+14.74s] DEBUG: Seat seat0: Exit status of /sbin/prime-offload: 0
[+14.74s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+14.74s] DEBUG: Session pid=1461: Started with service 'lightdm-greeter', username 'lightdm'
[+14.87s] DEBUG: Session pid=1461: Authentication complete with return value 0: Success
[+14.87s] DEBUG: Seat seat0: Session authenticated, running command
[+14.87s] DEBUG: Session pid=1461: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter
[+14.87s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+14.87s] DEBUG: Session pid=1461: Logging to /var/log/lightdm/seat0-greeter.log
[+15.34s] DEBUG: Activating VT 7
[+15.34s] DEBUG: Activating login1 session c1
[+15.34s] DEBUG: Seat seat0 changes active session to c1
[+15.34s] DEBUG: Session c1 is already active
[+16.41s] DEBUG: Greeter connected version=1.18.3 resettable=false
[+18.83s] DEBUG: Greeter start authentication for mariusz
[+18.83s] DEBUG: Session pid=1608: Started with service 'lightdm', username 'mariusz'
[+18.83s] DEBUG: Session pid=1608: Got 1 message(s) from PAM
[+18.83s] DEBUG: Prompt greeter with 1 message(s)
[+19.19s] DEBUG: User /org/freedesktop/Accounts/User112 added
[+26.83s] DEBUG: Continue authentication
[+26.84s] DEBUG: Session pid=1608: Authentication complete with return value 0: Success
[+26.84s] DEBUG: Authenticate result for user mariusz: Success
[+26.84s] DEBUG: User mariusz authorized
[+26.85s] DEBUG: Greeter requests session ubuntu
[+26.85s] DEBUG: Seat seat0: Stopping greeter; display server will be re-used for user session
[+26.85s] DEBUG: Session pid=1461: Sending SIGTERM
[+26.91s] DEBUG: Greeter closed communication channel
[+26.91s] DEBUG: Session pid=1461: Exited with return value 0
[+26.91s] DEBUG: Seat seat0: Session stopped
[+26.91s] DEBUG: Seat seat0: Greeter stopped, running session
[+26.91s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+26.92s] DEBUG: Session pid=1608: Running command /usr/sbin/lightdm-session gnome-session --session=ubuntu
[+26.92s] DEBUG: Creating shared data directory /var/lib/lightdm-data/mariusz
[+26.92s] DEBUG: Session pid=1608: Logging to .xsession-errors
[+26.97s] DEBUG: Activating VT 7
[+26.97s] DEBUG: Activating login1 session c2
[+26.97s] DEBUG: Seat seat0 changes active session to c2
[+26.97s] DEBUG: Session c2 is already active
[+53.95s] DEBUG: Seat seat0 changes active session to
[+59.71s] DEBUG: Seat seat0 changes active session to 1
[+63.94s] DEBUG: Got signal 15 from process 1
[+63.94s] DEBUG: Caught Terminated signal, shutting down
[+63.94s] DEBUG: Stopping display manager
[+63.94s] DEBUG: Seat seat0: Stopping
[+63.94s] DEBUG: Seat seat0: Stopping display server
[+63.94s] DEBUG: Sending signal 15 to process 1103
[+63.94s] DEBUG: Seat seat0: Stopping session
[+63.94s] DEBUG: Session pid=1608: Sending SIGTERM
[+64.00s] DEBUG: Session pid=1608: Terminated with signal 1
[+64.00s] DEBUG: Seat seat0: Session stopped
[+64.17s] DEBUG: Seat seat0 changes active session to
[+64.17s] CRITICAL: session_get_login1_session_id: assertion 'session != NULL' failed
[+64.46s] DEBUG: Process 1103 exited with return value 0
[+64.46s] DEBUG: DisplayServer x-0: X server stopped
[+64.46s] DEBUG: Releasing VT 7
[+64.46s] DEBUG: DisplayServer x-0: Removing X server authority /var/run/lightdm/root/:0
[+64.46s] DEBUG: Seat seat0: Display server stopped
[+64.46s] DEBUG: Launching process 2775: /sbin/prime-switch
[+64.60s] DEBUG: Process 2775 exited with return value 0
[+64.60s] DEBUG: Seat seat0: Exit status of /sbin/prime-switch: 0
[+64.60s] DEBUG: Seat seat0: Stopped
[+64.60s] DEBUG: Display manager stopped
[+64.60s] DEBUG: Stopping daemon
[+64.60s] DEBUG: Exiting with return value 0
[+0.11s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.29s] DEBUG: Starting Light Display Manager 1.18.3, UID=0 PID=1058
[+0.29s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.29s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-disable-log-backup.conf
[+0.29s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
[+0.29s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
[+0.29s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
[+0.29s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
[+0.29s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
[+0.29s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/90-nvidia.conf
[+0.29s] DEBUG: [SeatDefaults] is now called [Seat:*], please update this configuration
[+0.29s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.29s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.29s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.29s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.29s] DEBUG: Registered seat module xlocal
[+0.29s] DEBUG: Registered seat module xremote
[+0.29s] DEBUG: Registered seat module unity
[+0.29s] DEBUG: Monitoring logind for seats
[+0.29s] DEBUG: New seat added from logind: seat0
[+0.29s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.29s] DEBUG: Seat seat0: Starting
[+0.29s] DEBUG: Seat seat0: Creating greeter session
[+0.45s] DEBUG: Seat seat0: Creating display server of type x
[+0.45s] DEBUG: Quitting Plymouth
[+0.47s] DEBUG: Using VT 7
[+0.47s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.47s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.47s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.47s] DEBUG: DisplayServer x-0: Launching X Server
[+0.47s] DEBUG: Launching process 1096: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.47s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.47s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.47s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.54s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.54s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+15.79s] DEBUG: Got signal 10 from process 1096
[+15.79s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+15.79s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+15.79s] DEBUG: Launching process 1307: /sbin/prime-offload
[+15.79s] DEBUG: Process 1307 exited with return value 0
[+15.79s] DEBUG: Seat seat0: Exit status of /sbin/prime-offload: 0
[+15.79s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+15.79s] DEBUG: Session pid=1313: Started with service 'lightdm-greeter', username 'lightdm'
[+15.87s] DEBUG: Session pid=1313: Authentication complete with return value 0: Success
[+15.87s] DEBUG: Seat seat0: Session authenticated, running command
[+15.87s] DEBUG: Session pid=1313: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter
[+15.87s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+15.87s] DEBUG: Session pid=1313: Logging to /var/log/lightdm/seat0-greeter.log
[+16.53s] DEBUG: Activating VT 7
[+16.53s] DEBUG: Activating login1 session c1
[+16.53s] DEBUG: Seat seat0 changes active session to c1
[+16.53s] DEBUG: Session c1 is already active
[+18.42s] DEBUG: Greeter connected version=1.18.3 resettable=false
[+20.41s] DEBUG: Greeter start authentication for mariusz
[+20.41s] DEBUG: Session pid=1652: Started with service 'lightdm', username 'mariusz'
[+20.42s] DEBUG: Session pid=1652: Got 1 message(s) from PAM
[+20.42s] DEBUG: Prompt greeter with 1 message(s)
[+20.84s] DEBUG: User /org/freedesktop/Accounts/User112 added
[+44.49s] DEBUG: Continue authentication
[+44.50s] DEBUG: Session pid=1652: Authentication complete with return value 0: Success
[+44.50s] DEBUG: Authenticate result for user mariusz: Success
[+44.50s] DEBUG: User mariusz authorized
[+44.50s] DEBUG: Greeter requests session ubuntu
[+44.50s] DEBUG: Seat seat0: Stopping greeter; display server will be re-used for user session
[+44.50s] DEBUG: Session pid=1313: Sending SIGTERM
[+44.59s] DEBUG: Greeter closed communication channel
[+44.59s] DEBUG: Session pid=1313: Exited with return value 0
[+44.59s] DEBUG: Seat seat0: Session stopped
[+44.59s] DEBUG: Seat seat0: Greeter stopped, running session
[+44.59s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+44.59s] DEBUG: Session pid=1652: Running command /usr/sbin/lightdm-session gnome-session --session=ubuntu
[+44.59s] DEBUG: Creating shared data directory /var/lib/lightdm-data/mariusz
[+44.59s] DEBUG: Session pid=1652: Logging to .xsession-errors
[+44.63s] DEBUG: Activating VT 7
[+44.63s] DEBUG: Activating login1 session c2
[+44.63s] DEBUG: Seat seat0 changes active session to c2
[+44.63s] DEBUG: Session c2 is already active