Session briefly starts then immediately crashes; User authentication problem?

Unfortunately, nothing useful afaict:

Setting VNC password...
Starting VNC server...

Desktop 'TurboVNC: axis1:3 (erik-k)' started on display axis1:3

Log file is vnc.log
Successfully started VNC server on axis1.stor:5903...
Script starting...
Starting websocket server...
ERROR: Collection default cannot be found
Launching desktop 'gnome'...
cat: /etc/xdg/autostart/gdu-notification-daemon.desktop: No such file or directory
WebSocket server settings:
  - Listen on :23775
  - No SSL/TLS support (no cert file)
  - Backgrounding (daemon)
Scanning VNC log file for user authentications...
Generating connection YAML file...
/home/users/erik-k/ondemand/data/sys/dashboard/batch_connect/sys/bc_desktop/axis/output/cdcf0eec-fb7b-4f4d-8618-184da191f4ec/desktops/gnome.sh: line 17: 2200206 Terminated              /etc/X11/xinit/Xsession gnome-session
Desktop 'gnome' ended...
Cleaning up...
Killing Xvnc process ID 2200151

Here is a reference from a working session after I separately logged in,

Setting VNC password...
Starting VNC server...

Desktop 'TurboVNC: axis1:3 (erik-k)' started on display axis1:3

Log file is vnc.log
Successfully started VNC server on axis1.stor:5903...
Script starting...
Starting websocket server...
ERROR: Collection default cannot be found
Launching desktop 'gnome'...
WebSocket server settings:
  - Listen on :27851
  - No SSL/TLS support (no cert file)
  - Backgrounding (daemon)
cat: /etc/xdg/autostart/gdu-notification-daemon.desktop: No such file or directory
Scanning VNC log file for user authentications...
Generating connection YAML file...
Setting VNC password...
Generating connection YAML file...
Setting VNC password...
Generating connection YAML file...
Desktop 'gnome' ended...
Cleaning up...
Killing Xvnc process ID 2201160