vncviewer: VNC server closed connection

So I installed a VNC server (Tight VNC) on my workstation 'orac' which is running Debian Jessie with KDE Plasma. And a VNC client (also Tight VNC) on my workstation 'tact' running Debian Stretch with KDE Plasma. I ran vncpasswd on orac to configure the password. I want to use VNC to use 'orac' from 'tact'. From tact I ssh'ed to orac and started the vncserver: jj5@orac:~$ vncserver New 'X' desktop is orac:1 Starting applications specified in /home/jj5/.vnc/xstartup Log file is /home/jj5/.vnc/orac:1.log Then from a console on tact I ran: jj5@tact:~$ vncviewer orac:1 Connected to RFB server, using protocol version 3.8 Enabling TightVNC protocol extensions Performing standard VNC authentication Password: Authentication successful Desktop name "jj5's X desktop (orac:1)" VNC server default format: 32 bits per pixel. Least significant byte first in each pixel. True colour: max red 255 green 255 blue 255, shift red 16 green 8 blue 0 Using default colormap which is TrueColor. Pixel format: 32 bits per pixel. Least significant byte first in each pixel. True colour: max red 255 green 255 blue 255, shift red 16 green 8 blue 0 vncviewer: VNC server closed connection Before vncviewer: VNC server closed connection is reported everything seems to be working smoothly. A window opens, I see KDE Plasma doing it's login/loading thing, then my orac desktop loads, a bunch of default Dolphin windows load, and KDE Plasma starts processing my autostart scripts, so everything seems to be working fine, and then almost as soon as it starts KDE/VNC disappears and shuts down usually with vncviewer: VNC server closed connection but sometimes with vncviewer: read: Connection reset by peer instead. So why is KDE (or VNC?) bailing just as soon as it starts? Any help greatly appreciated! p.s. here's some extra info about the environment on the VNC server (orac): jj5@orac:~/.vnc$ ls -al total 24K drwx------ 2 jj5 jj5 4.0K May 4 17:35 ./ drwxr-xr-x 74 jj5 jj5 4.0K May 4 17:35 ../ -rw-r--r-- 1 jj5 jj5 1.3K May 4 17:36 orac:1.log -rw-r--r-- 1 jj5 jj5 5 May 4 17:35 orac:1.pid -rw------- 1 jj5 jj5 8 May 4 15:52 passwd -rwxr-xr-x 1 jj5 jj5 263 May 4 17:32 xstartup* And the log file says: jj5@orac:~/.vnc$ cat orac\:1.log 04/05/17 17:35:57 Xvnc version TightVNC-1.3.9 04/05/17 17:35:57 Copyright (C) 2000-2007 TightVNC Group 04/05/17 17:35:57 Copyright (C) 1999 AT&T Laboratories Cambridge 04/05/17 17:35:57 All Rights Reserved. 04/05/17 17:35:57 See http://www.tightvnc.com/ for information on TightVNC 04/05/17 17:35:57 Desktop name 'X' (orac:1) 04/05/17 17:35:57 Protocol versions supported: 3.3, 3.7, 3.8, 3.7t, 3.8t 04/05/17 17:35:57 Listening for VNC connections on TCP port 5901 04/05/17 17:36:04 Got connection from client 10.1.1.126 04/05/17 17:36:04 Using protocol version 3.8 04/05/17 17:36:04 Enabling TightVNC protocol extensions 04/05/17 17:36:06 Full-control authentication passed by 10.1.1.126 04/05/17 17:36:06 Pixel format for client 10.1.1.126: 04/05/17 17:36:06 32 bpp, depth 24, little endian 04/05/17 17:36:06 true colour: max r 255 g 255 b 255, shift r 16 g 8 b 0 04/05/17 17:36:06 no translation needed 04/05/17 17:36:06 Using tight encoding for client 10.1.1.126 04/05/17 17:36:06 Using compression level 1 for client 10.1.1.126 04/05/17 17:36:06 Using image quality level 6 for client 10.1.1.126 04/05/17 17:36:06 Enabling X-style cursor updates for client 10.1.1.126 04/05/17 17:36:06 Enabling cursor position updates for client 10.1.1.126 04/05/17 17:36:06 Enabling LastRect protocol extension for client 10.1.1.126 Note that 10.1.1.126 is my VNC client 'tact'. My xstartup script is pretty much just the default one (I don't have an ~/.Xresources file so I removed that from the xrdb command, otherwise it's as-is): jj5@orac:~/.vnc$ cat xstartup #!/bin/sh #xrdb $HOME/.Xresources xrdb xsetroot -solid grey #x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" & #x-window-manager & # Fix to make GNOME work export XKL_XMODMAP_DISABLE=1 /etc/X11/Xsession