Вот что выводит:
username@linux-emak:~> VirtualBox
VirtualBox: Error -10 in SUPR3HardenedMain!
VirtualBox: Effective UID is not root (euid=1000 egid=100 uid=1000 gid=100)
VirtualBox: Tip! It may help to reinstall VirtualBox.
username@linux-emak:~> Gtk-Message: (for origin information, set GTK_DEBUG): failed to retrieve property `GtkTreeView::odd-row-color' of type `GdkColor' from rc file value "((GString*) 0x819e9d0)" of type `GString'
<html><b>Effective UID is not root (euid=1000 egid=100 uid=1000 gid=100) (rc=-10)</b><br/><br/>Please try reinstalling VirtualBox.</html>
