I've seen this, and it appears to be due to having /etc/dbus-1/system.d/xorg-server.conf from xserver-xorg-core. After uninstalling xserver-xorg-core, things work again. Of course, if you need both xserver-xorg-core and Xvfb, then this won't work for you--you'll probably have to edit the dbus config.
I've seen this, and it appears to be due to having /etc/dbus- 1/system. d/xorg- server. conf from xserver-xorg-core. After uninstalling xserver-xorg-core, things work again. Of course, if you need both xserver-xorg-core and Xvfb, then this won't work for you--you'll probably have to edit the dbus config.