Unity HoloLens 2 deployed App stuck loading

Question

I am trying to deploy an app from Unity 2020.3.32f1 to the Hololens 2 with Visual Studio 2022 over USB. Everytime I try to deploy the app, it builds and deploys through visual studio correctly before it begins to load in the Hololens, it then gets stuck on 4 spinning spheres and remains here until I open the start menu and click home.

I have tried building an app following the process defined here https://learn.microsoft.com/en-us/learn/paths/beginner-hololens-2-tutorials/ and still end up stuck trying to load the app with 4 endlessly spinning white spheres.

I am using MRTK 2.7.3 & Mixed Reality OpenXR Plugin 1.3.1 installed from the Mixed Reality Feature Tool Unity 2022.3.32f1 Visual Studio 2022

The previous project I was working with using MRTK 2.5.1, Unity 2019.4.28f1, visual studio 2022 and no OpenXR, with all the same settings works perfectly.

Below are the Build and Player Settings I am using

Build Settings

XR Plugin Management Settings

OpenXR Settings

Spurling

According to your post, it may be the Visual Studio Debugger failed to launch the app. Could you rebuild your Unity project into another new folder to ensure the VS project is clean and build & deploy the Solution to your HoloLens without Visual Studio Debugger connecting? Do you see the same behavior? – Arrowwood

I have done serveral rebuilds of the project, as well as starting a project from scratch following the Microsoft MRTK getting started page all resulting in the same error, also if I stop visual studio, and launch the deployed app from within the hololens it leads to the same error. I have not had any issues deploying and using serveral apps developed with an older version of Unity and MRTK and no OpenVR. – Spurling

Answer 1

This is fixed in Unity 2020.3.33f1 which was just released. A workaround was given by disabling the Splash screen in the Unity Editor.

Here the release notes. https://unity3d.com/de/unity/whats-new/2020.3.33

And the bug tracker entry. https://issuetracker.unity3d.com/issues/app-doesnt-launch-on-hl2-uwp-after-update-to-2020-dot-3-32f1

I tried it by my self and it worked.

My Environment:

• Unity 2020.3.33f1
• MRTK 2.7.3
• Visual Studio 2019
• OpenXR Plugin 1.3.1
• XR Plugin Management 4.2.1

Hockenberry

Answer 2

I have this exact same issue. Same version of unity & using Visual Studio 2022. Everything was working with Unity 2020.3.20f1 => Upgrade to 2020.3.32f1 and the problem (infinite loading spheres) occurs.

Reverting back to version 2020.3.20f1 & clearing the build folder has fixed the issue for me.

Apologies for not giving any understanding as to why this may be occurring, I can only inform you that reverting to a previous unity build will more than likely fix the problem (As you are probably aware).

Lamar

Same here, expect I updated from 2020.3.28f1. Returning back to previous version solved the issue. – Phonetics

So eventually after reinstalling Visual Studio, Unity and all related tools only to end up back with the same error, I created a new project on a different computer (in exactly the same way with ethe same versions of everything) and it works fine. It even worked copying the new project onto the original computer I was using. So frustrating that I don't know what caused the issue, but at least I can continue working. – Spurling