Warning: Failed to find an open display

When launching a FastX session you may get the following message Warning: Failed to find an open display

Background

By default, FastX will check for open Displays on the Server.

FastX checks the location /tmp/.X11-unix/ for open Displays

The DisplayBase and DisplayLimit are set in /etc/xdg/StarNet\ Communications/FastX\ Server.conf

You will receive this error message if the FastX Server cannot find any open Displays to connect to.

Solution

There are several options available:

  1. Remove unused (or old) Displays from the /tmp/.X11-unix/ directory.
    WARNING: Deleting files in this directory may cause other applications to malfunction. Only delete these files if you understand the way Displays work
  2. Increase the DisplayLimit in /etc/xdg/StarNet\ Communications/FastX\ Server.conf so that FastX will check for more open Displays.
  3. Change the DisplayBase in /etc/xdg/StarNet\ Communications/FastX\ Server.conf to ensure that other programs are not conflicting and creating Displays<

A combination of Option #2 and #3 work best.

For option #2 and #3, you must kill and restart the fastx_server for the changes to take effect.
Existing sessions will not be affected by restarting the server.