I can't get beyond the graphical login screen since I ran apt-get upgrade on my brand new Ubuntu Dell with Ubuntu 14.04
The permissions on .Xauthority, .ICEauthority, and /tmp are correct. Reinstalling lightdm did not help; I tried that three times in various variants. Switching over to gdm caused a black-screen nightmare that took me half an hour to solve, and I'm back to lightdm. I installed linux-generic, and it didn't help. That exhausts everything suggested on this site. I have an nvidia card. Any idea what I can do?
Here is the content of .xsession-errors:
init: gnome-session (Unity) main process (2195) terminated with status 1
init: unity-settings-daemon main process (2182) killed by TERM signal
init: Disconnected from notified D-Bus bus
init: logrotate main process (2097) killed by TERM signal
init: update-notifier-crash (/var/crash/lightdm.0.crash) main process (2130) killed by TERM signal
init: update-notifier-crash (/var/crash/_usr_bin_software-properties-gtk.1001.crash) main process (2131) killed by TERM signal
init: update-notifier-crash (/var/crash/_usr_bin_unity-control-center.1001.crash) main process (2133) killed by TERM signal
init: xsession-init main process (2173) killed by TERM signal
init: hud main process (2189) killed by TERM signal
init: unity-panel-service main process (2197) killed by TERM signal
I have resinstalled Ubuntu twice to fix various problems, but the login loop happens every time, except for the first login after each installation.
And this is the result of grep -i nvidia in /var/log/Xorg.0.log
[ 74.238] (II) Module glx: vendor="NVIDIA Corporation"
[ 74.238] (II) NVIDIA GLX Module 375.66 Mon May 1 14:28:39 PDT 2017
[ 74.238] (==) Matched nvidia as autoconfigured driver 0
[ 74.238] (II) LoadModule: "nvidia"
[ 74.239] (II) Loading /usr/lib/x86_64-linux-gnu/xorg/extra-modules/nvidia_drv.so
[ 74.239] (II) Module nvidia: vendor="NVIDIA Corporation"
[ 74.239] (II) NVIDIA dlloader X Driver 375.66 Mon May 1 14:03:26 PDT 2017
[ 74.239] (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs
[ 74.239] (II) NOUVEAU driver for NVIDIA chipset families :
[ 74.251] (EE) NVIDIA: Failed to initialize the NVIDIA kernel module. Please see the
[ 74.251] (EE) NVIDIA: system's kernel log for additional error messages and
[ 74.251] (EE) NVIDIA: consult the NVIDIA README for details.
[ 74.383] (EE) Failed to initialize GLX extension (Compatible NVIDIA X driver not found)