I found the reason, it's the file ~/.local/share/applications/gnome- wm.desktop. I attached here. So why does it prevents a window manager from being started?
** Attachment added: "gnome-wm.desktop" http://launchpadlibrarian.net/43530345/gnome-wm.desktop -- Window manager not started after login https://bugs.launchpad.net/bugs/538964 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is a bug assignee. -- desktop-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
