Xubuntu 18.04 : TigerVNC gives a black screen in the viewer

[DLCBurggraaff]

Xubuntu 18.04 : TigerVNC gives a black screen in the viewer.

In Xubuntu 16.04 I used the TigerVNC 1.8.0 debs as provided by upstream (https://bintray.com/tigervnc/stable/tigervnc/1.8.0#files/ubuntu-16.04LTS%2Famd64).

For Xubuntu 18.04 however upstream points to the Ubuntu repositories. I installed the 1.7.0 tigervnc-{common,viewer,{scraping,standalone}-server} debs I found there.

I noticed that the /usr/bin/vncserver script was rewritten. Using this new version (vncserver :60) gives a huge black screen in the viewer. It looks like the ~/.vnc/config file is ignored and that X is not started.

Luckily the upstream vncserver (.orig) script is also provided. Using that one gives a normally sized, but still black screen. It looks like the ~/.vnc/config file honoured now, but that X is still not started.

There is nothing noteworthy in the ~/.vnc/<host>:60.log file. The ~.xsession-errors file however reports:
-- Xsession: X session started for root at Sun Apr 29 17:47:33 CEST 2018
-- dbus-update-activation-environment: setting DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/0/bus
-- dbus-update-activation-environment: setting DISPLAY=:60
.....
-- /usr/bin/x-session-manager: X server already running on display :60
-- xfce4-session: Another session manager is already running

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: tigervnc-standalone-server 1.7.0+dfsg-8ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: XFCE
Date: Sun Apr 29 17:50:54 2018
SourcePackage: tigervnc
UpgradeStatus: No upgrade log present (probably fresh install)

[DLCBurggraaff (burdi)]

Actually using the tightvncserver or vnc4server packages also give a black/grey screen in the viewer ...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.