Description

Regression from 4.26 where actions fail to bind when remoting in 4.27

Repro:
using the Microsoft OpenXR Extensions plugin here:
https://github.com/microsoft/Microsoft-OpenXR-Unreal/tree/main/MsftOpenXRGame/Plugins/MicrosoftOpenXR

create a project
Opt-in to remoting from project settings/ Windows Mixed Reality/ Enable Remoting checkbox
restart (do not enter IP, or start the app remoting player on your HoloLens)
When the editor starts, launch the app remoting player on your HoloLens
Set the IP of your HoloLens in the remoting project settings window
Connect and VR Preview

Workaround:
If you have the AppRemotingPlayer running on your HoloLens when the editor starts, actions bind correctly.

Issues:
After connecting and VR Previewing, an assert fires here:
https://github.com/EpicGames/UnrealEngine/blob/f92703848301146ac68f828935b31be65364a2c8/Engine/Plugins/Runtime/OpenXR/Source/OpenXRInput/Private/OpenXRInput.cpp#L547
With error:
OpenXR call failed with result XR_ERROR_ACTIONSET_NOT_ATTACHED
> XR_ENSURE(xrSyncActions(Session, &SyncInfo));

Same assert fires in FOpenXREyeTracker::PostSyncActions:
> XR_ENSURE(xrGetActionStatePose(InSession, &GetActionStateInfo, &ActionStatePose));

Same assert fires in FOpenXRInput::SendControllerEvents()
> XR_ENSURE(xrGetCurrentInteractionProfile(Session, Subaction, &Profile));

Then at runtime, there will be constant spam like this and input events fail to register:
> ERROR (OpenXR) : Action 'right-controller-grip-pose' is not attached to this session.

OpenXR Spec:
[Link Removed]

If any action sets not attached to this session are passed to xrSyncActions it must return XR_ERROR_ACTIONSET_NOT_ATTACHED.

Remoting creates a new OpenXR session, it seems that the game's actions are not being properly attached to this session

Steps to Reproduce

create a project
Opt-in to remoting from project settings/ Windows Mixed Reality/ Enable Remoting checkbox
restart (do not enter IP, or start the app remoting player on your HoloLens)
When the editor starts, launch the app remoting player on your HoloLens
Set the IP of your HoloLens in the remoting project settings window
Connect and VR Preview

Have Comments or More Details?

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Fixed
ComponentXR
Affects Versions4.27
Target Fix4.27
Fix Commit16912339
Release Commit16912339
CreatedJul 13, 2021
ResolvedJul 21, 2021
UpdatedAug 5, 2021