VNC remote desktop - screen is black

Question

My system consists of a laptop running Ubuntu 18.04 LTS and a server running Centos 7. I installed tigervnc on the Centos machine, and set it all up for one user to access the machine using Remmina remote desktop. I used the following guide. It works fine for the 1st user I set this up for, but for the second user I set this up for the desktop appears black. Both users have the same configuration with the only changes being the numbering and user credentials in the configuration. I am at a loss why it doesn't work for the second user.

I created the vnc files by login in as the user and running the command:

vncserver

completed the fields required, after which the required files are created in the user home folder structure. I did this for the 1st and then the second user.

I then copied the file:

sudo cp /lib/systemd/system/[email protected]  /etc/systemd/system/vncserver@:2.service

Below is the content of the /home/<username>/.vnc/xstartup for the second user, note that is exactly the same as the first except for the user credentials:

#!/bin/sh

unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
gnome-session –session=gnome-classic &
gnome-panel&

The content of the /etc/systemd/system/vncserver@\:2.service file:

[Unit]
Description=Remote desktop service (VNC)
After=syslog.target network.target

[Service]
Type=forking

# Clean any existing files in /tmp/.X11-unix environment
ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
ExecStart=/usr/sbin/runuser -l <username> -c "/usr/bin/vncserver %i -geometry 1280x1024"
PIDFile=/home/<username>/.vnc/%H%i.pid
ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'

[Install]
WantedBy=multi-user.target

with <username> being replaced with the user login.

I start the vnc process using the following, making sure that I have stopped and disabled the 1st users vnc session:

sudo systemctl daemon-reload
sudo systemctl enable vncserver@:2.service
sudo systemctl start vncserver@:2.service
sudo systemctl status vncserver@:2.service

with output:

● vncserver@:2.service - Remote desktop service (VNC)
   Loaded: loaded (/etc/systemd/system/vncserver@:2.service; enabled; vendor preset: disabled)
   Active: active (running) since Thu 2020-02-06 09:44:37 GMT; 6s ago
  Process: 952 ExecStart=/usr/sbin/runuser -l <username> -c /usr/bin/vncserver %i -geometry 1280x1024 (code=exited, status=0/SUCCESS)
  Process: 947 ExecStartPre=/bin/sh -c /usr/bin/vncserver -kill %i > /dev/null 2>&1 || : (code=exited, status=0/SUCCESS)
 Main PID: 1011 (Xvnc)
   CGroup: /system.slice/system-vncserver.slice/vncserver@:2.service
       ‣ 1011 /usr/bin/Xvnc :2 -auth /home/<username>/.Xauthority -desktop venus:2 (<username>) -fp catalogue:/etc/...

Feb 06 09:44:33 venus systemd[1]: Starting Remote desktop service (VNC)...
Feb 06 09:44:37 venus systemd[1]: Started Remote desktop serv

the output of the log file /home/<username>/.vnc/venus\:2.log:

Xvnc TigerVNC 1.8.0 - built Aug  9 2019 03:04:19
Copyright (C) 1999-2017 TigerVNC Team and many others (see README.txt)
See http://www.tigervnc.org for information on TigerVNC.
Underlying X server release 12001000, The X.Org Foundation


Thu Feb  6 09:44:34 2020
 vncext:      VNC extension running!
 vncext:      Listening for VNC connections on all interface(s), port 5902
 vncext:      created VNC server for screen 0
/home/<username>/.vnc/xstartup: line 15: gnome-panel: command not found
GLib-GIO-Message: 09:44:37.641: Using the 'memory' GSettings backend.  Your settings will not be saved or shared with other applications.

** (process:1046): WARNING **: 09:44:37.688: Could not make bus activated clients aware of XDG_CURRENT_DESKTOP=GNOME environment variable: Could not connect: Connection refused

Thu Feb  6 09:44:50 2020
 Connections: accepted: 10.0.12.148::59266
 SConnection: Client needs protocol version 3.8
 SConnection: Client requests security type VeNCrypt(19)
 SVeNCrypt:   Client requests security type TLSVnc (258)

Thu Feb  6 09:44:53 2020
 VNCSConnST:  Server default pixel format depth 24 (32bpp) little-endian rgb888
 VNCSConnST:  Client pixel format depth 15 (16bpp) little-endian rgb555

Thu Feb  6 09:45:19 2020
 Connections: closed: 10.0.12.148::59266 (Clean disconnection)
 EncodeManager: Framebuffer updates: 1
 EncodeManager:   Tight:
 EncodeManager:     Solid: 1 rects, 1.31072 Mpixels
 EncodeManager:            15 B (1:174763 ratio)
 EncodeManager:   Total: 1 rects, 1.31072 Mpixels
 EncodeManager:          15 B (1:174763 ratio)
 TLS:         TLS session wasn't terminated gracefully
 ComparingUpdateTracker: 0 pixels in / 0 pixels out
 ComparingUpdateTracker: (1:-nan ratio)

This bit of the log file seems to be different from the log file created for the 1st user: ** (process:1046): WARNING **: 09:44:37.688: Could not make bus activated clients aware of XDG_CURRENT_DESKTOP=GNOME environment variable: Could not connect: Connection refused

Any help will be appreciated.

Solution

It turns out that the solution is to remove the Anaconda framework from the $PATH environment variable. So in my case the users /home/<username>/.bashrc file needs the following field commented out to look something like:

#__conda_setup="$('/home/<username>/anaconda3/bin/conda' 'shell.bash' 'hook' 2> /dev/null)"
#if [ $? -eq 0 ]; then
#    eval "$__conda_setup"
#else
#    if [ -f "/home/<username>/anaconda3/etc/profile.d/conda.sh" ]; then
#        . "/home/<username>/anaconda3/etc/profile.d/conda.sh"
#    else
#        export PATH="/home/<username>/anaconda3/bin:$PATH"
#    fi
#fi
#unset __conda_setup

Run source .bashrc. Remote desktop is then possible. Once the connection is established and you are on the remote desktop, uncomment the above lines and run source .bashrc to be able to use Anaconda within the remote desktop session.