Unity 2019.4.3 steamvr asset pack - HMD/controllers not being used, defaults to stereo display

I’m using Unity 2019.4.3 (I must use this version for university). I have downloaded the latest version of Valve’s SteamVR Plugin and I (believe) I am up to date with SteamVR.

For context I am using the Valve index and the knuckle controllers.

When launching the game I have the following view:

In the top left corner you can see controls that are used for the “Stereo Display (non head-mounted)” virtual reality SDK.
I can only assume that this is the default SDK used if something goes wrong.

Sound from the scene will play through the HMD, however when looking through it I am just stuck in the loading void (the scene with the dark mountains all around while a game is loading) and it says it is “waiting” for unity. It will do this indefinitely.

I have encountered two issues, one of which I believe is relevant to this problem and is a SteamVR warning that an interface is not found (105):

I have seen a couple posts about this but I have not found any solutions. This code is where the warning is thrown (I can’t dig any deeper because it goes to the compiled OpenVR API):

// Verify common interfaces are valid.

            OpenVR.GetGenericInterface(OpenVR.IVRCompositor_Version, ref error);
            if (error != EVRInitError.None)
                initializedState = InitializedStates.InitializeFailure;
                return null;

(if you want to look at the code yourself, this is part of the CreateInstance() method in SteamVR.cs)

When using a CameraRig instead of a Player the scene will work in the HMD, it also still throws the warning of the interface not being found. All the camera rig is is a camera, it does not allow further interaction with the world, so just using that is not suitable.

I’m not certain if the issue with interfaces is the root cause, but that’s why I’m posting here. I have no other leads to follow and me and a friend have been going nearly 4 hours trying to troubleshoot this and would greatly appreciate any advice.

Well I never got an answer nor did I find a solution, but I was allowed to use unity 20.1.4f1, where it did work.

For anyone who finds this post, using a later version of unity works, but if you are stuck on an older version, I’m afraid you’re on your own.