nDisplay target machine actively refused it

Anyone know why nDisplay has problems launching with the error in the title?

23/12/2020 23:25:06:  An error occurred while sending a command to EXCEPTION: No connection could be made because the target machine actively refused it

I have followed these instructions perfectly so I would guess that there is something wrong with my config file below?

I have 2 monitors plugged into a 2070 super and want to get nDisplay to run on these 2 monitors before trying anything remote on a separate PC.

I opened up the project example for nDisplay in UE4.26(Chaos preview) that so handilly comes in the launcher and have not modified anything there just built it as it was given to us by default and copied the demo_multiviewports.cfg example config file that comes with the project in the example folder.

My folder structure/files after doing a windows 10 build of that project is:

  • C:\WindowsNoEditor\Engine
  • C:\WindowsNoEditor\NDisplay
  • C:\WindowsNoEditor\demo_multiviewports.cfg
  • C:\WindowsNoEditor\Manifest_NonUFSFiles_Win64.txt
  • C:\WindowsNoEditor\NDisplay.exe
  • C:\WindowsNoEditor\nDisplayLauncher.exe

I have packaged the project as you can see above with no spaces in the folder structure. Then I launch nDisplayLauncher.exe and I select Applications as NDisplay.exe and choose the demo_multiviewports.cfg as the config and click run but always get an error that the target machine is refusing it.

This is the config I am using in that file.

[cluster_node] id="node_1" addr= window=wnd_center sound=true master=true
[cluster_node] id="node_2" addr= window=wnd_left 

[window] id=wnd_center fullscreen=false WinX=0 WinY=0 ResX=1920 ResY=1080 viewport=vp_center
[window] id=wnd_left fullscreen=false WinX=1920 WinY=0 ResX=1920 ResY=1080 viewport=vp_vp_left

[viewport] id=vp_center x=0 y=0 width=1920 height=1080 projection=proj_simple_center
[viewport] id=vp_left x=0 y=0 width=1920 height=1080 projection=proj_simple_left

[projection] id=proj_simple_center type=simple screen=scr_center
[projection] id=proj_simple_left type=simple screen=scr_left

[screen] id=scr_center loc="X=0,Y=0,Z=0" rot="P=0,Y=o,R=0" size="X=0.52,Y=0.29" parent=display_center
[screen] id=scr_left loc="X=0,Y=0,Z=0" rot="P=0,Y=o,R=0" size="X=0.52,Y=0.29" parent=display_left

[camera] id=camera_static loc="X=0,Y=0,Z=0" parent=socket_cam eye_swap=false eye_dist=0.064 force_offset=0

I have tried using all the various IP addresses found in cmd ipconfig like or or but no luck. Also tried cmd netstat to see if any ports were blocked and it looks ok to me.

I am at a bit of a loss here now. So any help would be most appreciated.

I figured out the problem.

  1. Make sure the nDisplayListener.exe is running “facepalm” - Copy it from C:\Program Files\Epic Games\UE_4.26Chaos\Engine\Binaries\DotNET\nDisplayListener.exe to your completed build folder. So in my case it was C:\WindowsNoEditor\nDisplayListener.exe
  2. Use the demo configuration file first and make sure that is working before trying to build your own custom one. C:\Users\yourUsername\Documents\Unreal Projects\NDisplay\Content\demo_multiviewports.cfg

This will run 4 synced windows on your primary monitor.