I was using VNC from RealVNC to access my Raspberry Pi 3B. However, the session suddenly stopped, and I get the following error message:
However, according to the RealVNC website, I should have a free license for noncommercial use. How do I fix this issue?
A new version of RealVNC Server was made available in the repositories yesterday. If you have recently updated your packages and installed this new version, then you will need to restart any running VNC server instances.
It's probably easiest to simply reboot if you can, but if not you can restart the servers.
If you're using the service mode server (i.e. the one that lets you connect to the console session), do:
sudo systemctl restart vncserver-x11-serviced
For virtual mode servers (started via the "vncserver" command), you will need to shutdown the virtual session and restart it. Do:
vncserver -kill DISPLAY
Where DISPLAY is the display number (probably :1 if you have only one virtual mode server running).
and restart the server as normal with the "vncserver" command.
I had no end of trouble with RealVNC. It was all fully licenced (personal), updated, and correctly install but PAM Unix login always failed leading to blacklisting. VNC password authentication worked but I ended up with a postage stamp sized screen. Disable with
systemctl disable vncserver-x11-serviced
and install TightVNCserver as above and use any VNC viewer and it just works. I'm sure with an Enterprise service-level agreement it would be wonderful but it shouldn't have been used for the Raspberry Pi.
I got stuck with the same problem on a Pi 2 running Jessie.
What finally worked for me is:
sudo apt-get install tightvncserver.
It cannot un-install realVNC, but disables it partly. After that I can use vncserver as normal:
-geometry 1920x1080 i.s.o. -randr=1920x1080)
