Debian :: X11vnc Fails After Jessie Upgrade

Using x11vnc server on Debian host, and TightVNC viewer client on Windows 7. All was working fine until a server host upgrade, from Wheezy to Jessie. Now, when I try to connect, TightVNC retrieves the certificate as normal, compares and accepts it, and starts stunnel. The next step would normally be to prompt for the VNC password.

Instead it gives an error:

ReadExact: Socket error while reading.

I'm guessing that some thing is missing or misconfigured after the Jessie upgrade, which broke many other things too, as Debian upgrades always seem to do. I have removed and reinstalled the x11vnc package, no effect.

The errors in the log file don't mean a lot to me.

The server is started with this command:

Code: Select allx11vnc -ssl -display :0 -usepw >>vnc-log 2>&1 &

If I start it up without the -ssl flag, and connect from the Windows system with a different client (Mobaxterm) it all goes well.

Relevant part (tail) of the server log file:

Code: Select allThe SSL VNC desktop is:  myhost:0
PORT=5900
SSLPORT=5900

19/01/2016 12:31:10 SSL: accept_openssl(OPENSSL_VNC)
19/01/2016 12:31:10 SSL: spawning helper process to handle: 192.168.2.3:51942
19/01/2016 12:31:10 SSL: helper for peerport 51942 is pid 11193:
19/01/2016 12:31:10 connect_tcp: trying:   127.0.0.1 20000

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