Vive Business Streaming - ViveOpenXRFacialTracking.dll xr api layer causes random crashes in unity OpenXR applications.

[vrp_vh]

Issue:

Applications sometimes crash during openxr initialization/startup when XR_APILAYER_VIVE_facial_tracking (ViveOpenXRFacialTracking.dll) is loaded.

versions:

VBS - 1.10.4

ViveOpenXRFacialTracking.dll - 0.1.6.0

Unity - 2021.3

OpenXR plugin - 1.6.0

Repro:

Cannot be reproduced consistently. Happens mostly when VBS  is running without steamvr and openxr is initialized manually inside unity script.

Sample app:

Unity application with unity OpenXR plugin v1.6.0 https://docs.unity3d.com/Packages/com.unity.xr.openxr@1.6/manual/index.html

One of the OpenXR plugin samples (InterceptFeature) can be used.

+ simple script (attatched in files) that would start and stop openxr loader on key press.

To achieve said crash:

1/ start VBS (without steamvr)

2/ start unity app

3/ press M (StartXR)

4/ if application did not crash kill vrserver.exe and goto step 3

Workaround A:

Disable facial tracking layer in system registry. HKEY_LOCAL_MACHINE\SOFTWARE\Khronos\OpenXR\1\ApiLayers\Implicit  - set facial tracking dword to something != 0

Workaround B:

Disable facial tracking layer using DISABLE_XR_APILAYER_VIVE_FACIAL_TRACKING_1 environment variable

 

XRSwitch.cs Editor.log htc_openxr_facial_tracking_20230118.txt crash.dmp htc_facial_tracking_crash.evtx