Thanks Chris, your hint solved the issue. I performed the following steps:
* sudo apt-get install compizconfig-settings-manager * In "System -> Preferences -> CompizConfig Settings Manager" category "General" I enabled "Gnome Compatibility" -- Gnome Compatibility not enabled on upgrade https://bugs.launchpad.net/bugs/331556 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
