I think that only applies if you are using Raspbian as your OS.

Since you are using Lubuntu, the regular *Linux-x*.deb installation file is what you would want.
Regardless, RealVNC may only be compatible with 16.04 LTS+, it does not mention 18.04.

If you can't install it via the .deb file
www.realvnc.com/download/file/vnc.files/...-6.3.1-Linux-x64.deb (64-bit version)
www.realvnc.com/download/file/vnc.files/...-6.3.1-Linux-x86.deb (32-bit version)
that's where the problem likely lies.

Unless...
Did you try those or did you try installing the Raspbian (ARM) version? That may not work.
I am also running RealVNC on my Raspberry Pi3 and since I am using Ubuntu MATE on it, I think I had to install the Linux-x64.deb version, NOT the Raspbian version, on it.

I downloaded both of those files above, and when I launch them the installer says "incorrect architecture".
PK

In that case I may have been mistaken. Since I am away from home, I can't check which version I actually have on my Pi3. Sorry if I wrote something misleading here. I do remember that I also went through this by trial and error, but in the end everything worked fine.
Jo

I am not installing on a Pi3, but a NanoPC T4 which uses a RK3399 cpu.

Got it. I was just saying that if your nanoPC uses the ARM architecture, then my statement that I installed a non-ARM version of RealVNC on my Pi3 was likely incorrect. I needed to amend that before someone else gets misled.

If you can't solve the vnc issue, you can go another way and use X11 ssh forwarding to get the remote session displayed on your Mac.

That should be relatively basic steps: installing the X Server port "XQuartz" on your Mac, using a terminal to login to the nanopc via "ssh -X user@ip", and launching commands from there. Apps will display their interface on your Mac.

-Eric

tightvnc seems popluar, I run vnc4server, but I couldn't find any thing specific for your combination.
This is a bit off the wall, but this blog might be a resource for you.
tech.scargill.net/nanopc-t4-from-friendlyarm/#more-9931
He just got his nanopc-t4 & install lubuntu and last post had run into your dbus issue.
Could let him know the fix and ask him which vnc server he is using.
/Tom

I use the vino VNC server on Ubuntu and the RealVNC client (the free one!!!) on my Mac. Vino needs to not be encrypted for this to work. By the way, I use the RealVNC client on my iPad as well and that works too.

Mde lots of progress tonight. I got Vino VCN to work, and connects from a local network well. Very responsive too.
But - I have two issues I need help with:

1. I need the system (Lubuntu) to start the VNC server automatically upon startup. As the machine will be headless, it needs to be a turnkey system. I'm not sure if Vino Vnc will allow that. If not, please suggest an alternative, noting that RealVNC does not work on the NanoPC T4.

2. As soon as I log off from my Mac, VNC server shuts down on the Lubuntu machine. I need it to stay active all the time.

Any help would be appreciated!

Peter

Have you tested x11vnc which is the simplest way to access your SBC ?
Are you familiar with shell script ?
I might provide you some shell scripts that might help you to install x11vnc so it could start at boot.
You can take a look there: github.com/Patrick-81/NAFABox/blob/maste.../install_comsetup.sh

Does your Lubuntu system boot into a desktop? My Ubuntu system does (it starts the MATE desktop) and IIRC yours into LXDE. You should be able to add a start up application that starts the vino server for you. That’s what I did and it works like a charm.

Also have a look at the vino config settings using the dconf editor. it could be dconf2. I am not sure so please check yourself. There should be an option to keep vino running after you disconnect.

Major breakthrough!
1. I got the NanoPC to login automatically upon booting.
2. It creates a hotspot automatically.
3. Starts the VNC server
4. Stays on after I quite my VNC client - and has no errors reconnecting over and over.

Now I just have two more task to figure out. Please offer suggestions!

A: I need the system to use a screen size of 1440 x 900 when headless (VNC). Right now it's a tiny block about 400x400 square!
B: need INDI Server to automatically start upon booting.

Then I will test it with my gear as a headless INDI controller for my Astro rig.

Making progress! Thanks all!