Seems related to nvidia driver. >From dmesg:
[ 4.854459] Bridge firewalling registered [ 5.046794] init: nvidia-prime main process (1507) terminated with status 127 [ 5.413350] systemd-logind[947]: Failed to start unit user@111.service: Unknown unit: user@111.service [ 5.413355] systemd-logind[947]: Failed to start user service: Unknown unit: user@111.service [ 5.416467] systemd-logind[947]: New session c1 of user lightdm. [ 5.416480] systemd-logind[947]: Linked /tmp/.X11-unix/X0 to /run/user/111/X11-display. reinstalling nvidia drivers do not make any difference What can I try? -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1403127 Title: Kubuntu 14.10: after 12 Dec update X doesn't start To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1403127/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp