OMFG. What a PITA! I tried, and tried, and tried some more to get Real VNC to work on my Udoo Neo with UdooBuntu 18.04 on it. What a waste of time.

I finally found this post. It said to try x11vnc instead. I did. It worked. Here are the steps, lifted from that post. Thanks to lr1729!

Install x11vnc:

sudo apt-get install x11vnc
sudo x11vnc -storepasswd yourVNCpasswordHERE /etc/x11vnc.pass
sudo nano /etc/systemd/system/x11vnc.service

And add the following in that file:

[Unit]
Description="x11vnc"
Requires=display-manager.service
After=display-manager.service

[Service]
ExecStart=/usr/bin/x11vnc -shared -forever -xkb -noxrecord -noxfixes -noxdamage -display :0 -auth guess -rfbauth /etc/x11vnc.pass
ExecStop=/usr/bin/killall x11vnc
Restart=on-failure
Restart-sec=2

[Install]
WantedBy=multi-user.target

Start it with:

sudo systemctl daemon-reload
sudo systemctl start x11vnc

and make it start on boot with

sudo systemctl enable x11vnc .

Woohoo!!!!

I then installed the Windows Real VNC client on my PC and connected to a new server at udooneo:5900 and tada, I’m in!!!!!

And, as a bonus, I can copy and paste from my Windows PC to my Neo via VNC.

Whew!

Now, maybe I can install the Alexa VDK. We shall see.