nainu, thank you for your comment. Disabling the "desktop effects" and disabling "AddARGBGLXVisuals" (not sure if both are necessary or just disabling desktop effects is enough) in my xorg.conf allowed me to log in normally to the "GNOME" session.
The xsession-errors file which I attached also lists an error message for Compiz. Have we verified that this is a bug caused by X.org/Compiz not playing nice with gnome-session and can I mark this bug as a duplicate of bug #125902? Or do you still want me to ask the question in the support tracker, Sebastien? -- GNOME session freezes to black screen, Failsafe GNOME session works fine https://bugs.launchpad.net/bugs/135228 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs