• 10 Aug 2023
  • 7 Minutes to read
  • Contributors
  • Dark


  • Dark

Article summary

Section 8: Troubleshooting

This section describes how to correct common issues that may occur.  

Section 8.1: Adjust Vive Trackers

This section describes how to correct the Vive Trackers if they are not working,


If the Vive Trackers are not tracking or if the ARFX Launcher (if available) is not able to automatically pull in the tracker serial numbers, double check the serial numbers. Use the following procedure:

  1. Connect the USB-A to Micro USB (for Tracker 2.0) or USB-A to USB-C (for Tracker 3.0) cable from the computer to the Vive Tracker
  2. Open the USBDeview on your desktop.
  3. In the USBDeview, under the Serial Number column, look for something that starts with LHR. It will be listed with a serial number. If it displays as green, this means it is active and connected to the machine.
    1. To differentiate between the two trackers, connect only one tracker at a time and see what shows up in USBDeview


BEST PRACTICE: It is recommended to label your trackers with their unique Serial Number for ease of identification on set. It is also recommended to label which wireless USB Dongle belongs to which tracker by identifying them as A, B, etc. for ease of future identification and troubleshooting. 

A two-Vive Tracker system is generally recommended, with a Calibration Vive Tracker and a Hero Vive Tracker, but if only one tracker is available, please be sure to use the same Serial Number of your one Vive Tracker for both Calibration Tracker and Hero Tracker fields.


If the Vive Trackers serial numbers are input correctly but are still not tracking, use SteamVR to help troubleshoot.  

  1. Quit out of Unreal Engine if project file is still open.
  2. Navigate to the SteamVR window or launch it if it is not on.  
  3. If SteamVR asks for a head-mounted display (HMD), launch the ARFX Launcher (if available) and click on Patch SteamVR button and relaunch SteamVR. Or refer to Section 2.5 SteamVR Software Set Up to do this step manually. This should remove the requirement for the HMD and show you any connected Vive Trackers and Base Stations.  
  4. If there are any missing Vive Trackers and/or Base Stations:  
    1. Double check USB cables and USB extension cables for Vive Trackers are fully connected into the Trackersand the computer.  
      1. If there is a lot of wireless/mobile interference in a space, it’s best to keep Vive Trackers wired instead of relying purely on the wireless dongle.  
      2. Asking nearby cast/crew members to turn off their mobile devices may also help improve tracking in general. 
    2. Make sure to position the trackers and base stations so they can see each other. Give it a few moments as it usually takes a few seconds before SteamVR will recognize a previously unconnected device.  
    3. Double check that the trackers have a green (active) or amber (active and charging) light showing on their LED light. 
      1. If a tracker LED light is showing blue or white instead, be sure to press the Vive Tracker button. This should turn it green or amber.  
    4. If using more than two Base Stations, make sure that all base stations are on their own unique channels.  
  5. If none of the above work, restart the computer and start up SteamVR and the Unreal Engine Scene powered with ARFX Pro Plugin again.  

SteamVR may stop tracking and go to sleep if the trackers have been unmoving or out of view of the Base Stations for too long. If this occurs, do the following:

  1. Close the UE4/5 project.
  2. Close or restart SteamVR, and then reopen it to repeat the pairing process with the tracker.

If the tracker has been lost entirely, will not repair, or the computer crashes, then restart the computer and set up the SteamVR and Unreal Engine again. 

Section 8.2: Tracking and Jittering Issues  

If you are having jitters with the tracking, 

  1. Make sure there isn’t any IR being reflected towards the puck 
    1. This can cause the puck to jitter and lose tracking, but the tracking will come back. 
    2. If you are losing tracking, make sure the puck isn’t being blocked, and it is being seen by the Base Stations. 
    3. It is possible someone may have accidently bumped one of the Base Stations while setting up. In this case you will just need to recalibrate.  
  2. If these solutions haven’t worked out, you can hardwire the puck using a USB-A to Micro-USB or USB-A to USB-C cable. This will stop the jitteriness.  

BEST PRACTICE: If tracking is jerky for a slow-moving hero camera shot: 

  • Unreal Engine 4:
    1. Lower the Positional Threshold and Angular Threshold values down by 0.01 or 0.001 increments at a time until the tracking is smooth. 
    2. If the hero tracker is sitting still but there is perceived jitter on the ARFX background, increase the Positional Threshold and Angular Threshold values up by 0.01 or 0.001 increments until the jitter no longer shows. 
  • Unreal Engine 5: 
    1. Lower the Positional Power Threshold and Angular Power Threshold values down by 1 increment at a time until the tracking is smooth. 
    2. If the hero tracker is sitting still but there is perceived jitter on the ARFX background, increase the Positional Power Threshold and Angular Power Threshold values up 1 increment until the jitter no longer shows. 

All wires used with ARwall should be the most up-to-date versions for best performance: 

  • HDMI should be minimum of 2.0. 
  • DisplayPort should be minimum 1.4. 
  • If converters are used, be sure to match the minimum versions listed above. 
  • USB-A Extension Cables should be a minimum of 2.0 or 3.0. If this cable needs to extend longer than 50 feet, fiber optic USB extension cables are recommended.  
    • It is recommended to plug trackers directly into the USB slots on the motherboard. Avoid plugging into USB hubs if tracking issues occur

Section 8.4: Unreal Engine System Issues 

If the Unreal Engine crashes, do the following:

  1. Click Closewithout resending.
  2. Re-open the UE4/5 project, play scene, and recalibrate the scene. The SteamVR engine is still running and tracking in the event of an Unreal Engine crash. Once you re-open the UE4/5 project, the SteamVR will continue tracking.
  3. Test the tracker for confirmation that it is working or verify by looking at the SteamVR window. 

Section 8.5: Project File Launch / Login Issues

  1.  If the Unreal project keeps closing or not opening the login window, a few different things may have happened:
    1. If the login window does not appear make sure to download .NET6 Runtime.
      1. This is required for the login window to communicate with our software. You can download your appropriate .NET6 Runtime here.
    2. Make sure your machine's language settings are set to English. Other languages can cause errors with the login system. We are currently working on a solution to support more language settings. 
    3. Make sure you use the same account to login that you used when first creating your account.
    4. Ensure you have no spaces at the beginning or end of your Activation Code when entering or copying and pasting it. 
    5. If you entered an incorrect Activation Code with your login and password, follow these steps for the Plugin.
      1. Open your project folder
      2. Locate the ‘Saved’ folder -> ‘Config’ folder -> ‘Windows’ folder -> delete the ‘ARwall.ini’ file
      3. Using the Windows search function, or pressing the Windows Key, type in '%appdata% and click Open to open this folder.
        1. WIthin the '%appdata%' folder, locate the 'ARwall' folder and delete this file: 'ARwall.Identity.Client.msalcache.bin'
        2. While in the same 'ARwall' folder, please open the 'ARwall.Identity.Client' (using notepad, if needed) and select the text information through a screenshot (Windows key + Shift key + S key and selecting the text) or by copying and pasting its contents and email to us at
      4. Then launch the Unreal Engine project and a prompt should ask you to enter your Activation Code and login again.
        1. The login page (via browser and usually pops up after Unreal Engine has reached 75% of opening) may open behind Unreal Engine, so please make sure to look for that browser window using Alt + Tab to search through your open windows. 

Section 8.6: Logging Out of One Machine to Use License on Another Machine

The ARFX Pro Plugin license is for a SINGLE seat tied to the machine that you initially log into. One single license can log into multiple Unreal Engine projects using the same ARFX Pro Plugin on the same machine. If there is a need to switch to another machine, log out of the current machine before logging into a new machine. Follow the steps below to log the single license out of a machine:  

  1. Navigate to and select the Settings Menu usually located in the upper right corner.
  2. Select Project Settings within that menu, which should open the Project Settings Menu.
  3. Scroll down on the left menu until you see the Plugins category and select ARwall.
  4. Click Log Off button and this should log off the single license from the machine. This only needs to be done once on one project file on the machine, and it should log out of all projects on the same machine.

Once fully logged out of the original machine, proceed to log into the new machine.

Was this article helpful?