No Active XR.ARSubsystems Warning and Black Screen depending on Unity version

I just wanted to know how serious these warnings are because if I build an iphone 14.2 app with Unity 2020.3.16 I get a black screen no matter what I do, but with 2021.1.17 I get the same warnings, but the build works. With 2019.4.29 I don’t get the warnings (but that’s probably because 2019 includes the AR subsystems package that I don’t see available in 2020 or 2021)

I’ve already looked for answers for why my 2020 version gives me a black screen: Black Screen and here No active UnityEngine.XR.ARSubsystems.XRDepthSubsystem is available. and in other places as well, but none of those solutions work for me.

I have Macbook Mid 2015 with Catalina 10.15.7 installed. I have Xcode 12.4 installed.

To ensure that it wasn’t any of my scripts I built the simplest AR build: Just AR session origin, session and the default point cloud and default plane. I get the following warning messages while in the editor:

No active UnityEngine.XR.ARSubsystems.XRSessionSubsystem is available. Please ensure that a valid loader configuration exists in the XR project settings.
UnityEngine.XR.ARFoundation.ARSession:OnEnable () (at Library/PackageCache/com.unity.xr.arfoundation@4.1.7/Runtime/AR/ARSession.cs:341)

No active UnityEngine.XR.XRInputSubsystem is available. Please ensure that a valid loader configuration exists in the XR project settings.
UnityEngine.XR.ARFoundation.ARInputManager:OnEnable () (at Library/PackageCache/com.unity.xr.arfoundation@4.1.7/Runtime/AR/ARInputManager.cs:24)

No active UnityEngine.XR.ARSubsystems.XRCameraSubsystem is available. Please ensure that a valid loader configuration exists in the XR project settings.
UnityEngine.XR.ARFoundation.SubsystemLifecycleManager`3<UnityEngine.XR.ARSubsystems.XRCameraSubsystem, UnityEngine.XR.ARSubsystems.XRCameraSubsystemDescriptor, UnityEngine.XR.ARSubsystems.XRCameraSubsystem/Provider>:OnEnable () (at Library/PackageCache/com.unity.xr.arfoundation@4.1.7/Runtime/AR/SubsystemLifecycleManager.cs:87)

As I said, on Unity 2020.3.16 I get a black screen and no combination of different versions of ARFoundation and ARkit and XR Plugin Management fix it.

On Unity 2021.1.1 I get the warnings but things work.

On Unity 2019.4.29 things work without warnings.

Can someone explain to me what these warnings really mean and if they are serious if I want to deploy to the app store later? I might just use 2019 out of warning phobia!

I’ve tested with many different versions, but these are the ones that worked on 2021; AR Foundation 4.1.7, ARKit 4.1.7 and XR Plugin Management 4.0.7

Thank you so much!

Please check the XR Plugin management window and make sure that the Loader is enabled and setup properly.

https://docs.unity3d.com/Packages/com.unity.xr.arfoundation@4.1/manual/migration-guide-3.html#xr-plug-in-management

I have the same problem since 4 days, the initialize XR on Startup and the plugin in providers ARCore for Android have the hook. Please help.

UnityEngine.XR.ARSubsystems.XRCameraSubsystemDescriptor, UnityEngine.XR.ARSubsystems.XRCameraSubsystems/Provider>OnEnable() (at LibraryPackageCache/com.unity.xr.arfoundation@4.2.7/Runtime/AR/SubsystemLifecycleManager.cs;68)

No Active XR.ARSubsystems and XR.XR subsystems is available

Not good, when Unity makes it so much complicated.