I found out something interesting: I installed the KDE-environment via software center. I observed the following behavior:
I always can work in Unity, I only can't switch to a tty after some time. If I use KDE, I work normally, but all of a sudden my entire system freezes. I also can't switch to a tty anymore. I think at the point where I simply can't switch to a tty in Unity anymore, the KDE- System freezes. -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-session in Ubuntu. https://bugs.launchpad.net/bugs/987220 Title: System does not power off reliably when "Shut Down" chosen from GUI To manage notifications about this bug go to: https://bugs.launchpad.net/indicator-session/+bug/987220/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs