I've fount that the vncserver doesn't start correctly after a power outage or non-normal shutdown.  It appears that file in the /tmp/.X11-unix directory is left after the reboot, and causes the startup to fail.

My solution at the moment is to have a script in cron.hourly that checks if it is running, and it not it removes the file, and restarts the service.

Example using port 88 (5988)
==========
run=`systemctl status vncserver@:88.service | grep running | cut -b 20-26`
if [ -z "$run" ] ; then
   rm /tmp/.X11-unix/X88
   systemctl start vncserver@:88.service
fi
==========

Should these files be removed automatically on a restart?
Is it a vncserver issue or a system issue or how things are suppose to work?

Thanks.