Repro Steps:
# Launch 21.2.19f1 editor and create a new blank project
# Install XR management + OpenXR
# Use the MRTK feature tool to install OpenXR WMR Features to the project
# enable the loader, feature group, etc. for HoloLens 2
# Build/Deploy to device
# Note crash at launch

I could not reproduce this in 21.3. However, this may be a priority for MS who seeks test coverage against LTS (21.2)

Callstack:

>    UnityPlayer.dll!GfxDeviceD3D11Base::WaitForLastPresentationAndGetTimestamp() Line 4151    C++
     UnityPlayer.dll!GfxDeviceClient::WaitForLastPresentationAndGetTimestamp() Line 246    C++
     UnityPlayer.dll!UnityPlayer::AppCallbacks::_AppThreadImplementation(void * param) Line 242    C++
     UnityPlayer.dll!UnityPlayer::AppCallbacks::_AppThread(void * param) Line 290    C++
     [External Code]    

Ren was not able to reproduce this but had other issues unrelated to this report but I'm reporting what I'm seeing and we'll tear down the onion layers as we go.