I've gotten Xpra to work with Xdummy on lubuntu 16.04 by by starting Xpra on a virtual console. This may not support your use case but it works for mine.
INSTALLATION sudo apt-get install xpra apt list xpra xpra/xenial,now 0.15.8+dfsg-1 amd64 [installed] sudo usermod -aG tty <USERNAME> USE FROM DESKTOP Workaround for 16.04 issues. Start xpra on a /dev/tty ll /dev/tty63 crw-r----- 1 root tty 4, 63 Jul 15 17:34 /dev/tty63 #group needs rw access to openvt tty sudo chmod 660 /dev/tty63 ll /dev/tty63 crw-rw---- 1 root tty 4, 63 Jul 15 17:34 /dev/tty63 openvt -c 63 -f -- xpra start :80 --daemon=no START WITH BOOT [Unit] Description=Xpra server [Service] Type=simple Environment=TTYNum=63 DISPLAY=:90 #openvt will execute as root so requires no permission change on /dev/tty## #then sudo to user running xpra ExecStart=/bin/openvt -c $TTYNum -f -v -w -- /usr/bin/sudo --user <USERNAME> --login /usr/bin/xpra start $DISPLAY --daemon=no ExecStop=/usr/bin/sudo --user <USERNAME> --login /usr/bin/xpra stop $DISPLAY [Install] WantedBy=graphical.target -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1589447 Title: Xdummy cannot be used in Xenial To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-dummy/+bug/1589447/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs