Public bug reported: I've had this happen a couple of times now since upgrading to 18.04: soon (perhaps within a minute) after logging in, Gnome session ends abruptly and I'm thrown back to the login screen. IIRC, in both instances this occurred on the first login after boot, so it does not reoccur on the subsequent re-login, and not on every login (very rarely in fact), and for now I have no better steps to reproduce this other than "boot, log in".
Bug #1663839 (reported against 17.04) seems similar, as does bug #1731428 (reported against 17.10). journalctl output during the issue: Apr 16 07:00:30 saegusa gnome-session[4342]: gnome-session-binary[4342]: WARNING: Application 'org.gnome.SettingsDaemon.Color.desktop' failed to register before timeout Apr 16 07:00:30 saegusa gnome-session-binary[4342]: WARNING: Application 'org.gnome.SettingsDaemon.Color.desktop' failed to register before timeout Apr 16 07:00:30 saegusa gnome-session-binary[4342]: Unrecoverable failure in required component org.gnome.SettingsDaemon.Color.desktop Apr 16 07:00:30 saegusa gnome-session[4342]: gnome-session-binary[4342]: CRITICAL: We failed, but the fail whale is dead. Sorry.... Apr 16 07:00:30 saegusa gnome-session-binary[4342]: CRITICAL: We failed, but the fail whale is dead. Sorry.... ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: gnome-settings-daemon 3.28.1-0ubuntu1 ProcVersionSignature: Ubuntu 4.15.0-15.16-generic 4.15.15 Uname: Linux 4.15.0-15-generic x86_64 ApportVersion: 2.20.9-0ubuntu4 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Mon Apr 16 17:07:14 2018 InstallationDate: Installed on 2016-10-13 (550 days ago) InstallationMedia: Ubuntu-Server 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=fi_FI.UTF-8 SHELL=/bin/bash SourcePackage: gnome-settings-daemon UpgradeStatus: No upgrade log present (probably fresh install) ** Affects: gnome-settings-daemon (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug bionic -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1764417 Title: Unrecoverable failure in required component org.gnome.SettingsDaemon.Color.desktop To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/1764417/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs