Same. Core samples have this error too.

Why oh why, Vuforia? I've been using your Unity SDK for years and there has not been any moment where I could expect it to "just work". It's always on an undefined state of bad/old documentation, exceptions, build errors, runtime not doing the same as the editor etc etc.

If your documentation is shit/incomplete, your implementation is on a constant state of flux, and not even your own demo code does what it says... how are we supposed to use it?

I'm having the exact same issues, mid air tracking doesn't seem to work at all in a fresh scene.

Ground plane just works.



Even on the vuforia ground plane sample, the mid air tracking button is blocked until i place something on the ground plane, after that it works properly. I tried setting it to be enabled beforehand, but then it just doesn't work at all.

I've spent a couple of days trying to solve this issue, it hasn't been fun.

Found a solution that works for me:

Disable the Mid Air Positioner Behaviour component in the Unity scene, then enable it once Vuforia has successfully set up (or whenever you first want to use it) like so:

void Start() {

    var vuforia = VuforiaARController.Instance;

    vuforia.RegisterVuforiaStartedCallback(OnVuforiaStarted);

}

private void OnVuforiaStarted() {

    FindObjectOfType<MidAirPositionerBehaviour>().enabled = true;

}

Yep, I just started and followed the guide here: 

https://library.vuforia.com/articles/Solution/ground-plane-guide.html

After unpausing, the object is displayed in midair, but that error still showed up. 

This is with the most recent 2018.2.0b2 (beta version downloaded a week ago). 

Hey Adam and Vuforia Team...

I am having the same problem...

Using fresh Unity Beta 2018

NullReferenceException: Object reference not set to an instance of an object

Vuforia.MidAirPositionerBehaviour.SetupIndicator ()

Vuforia.MidAirPositionerBehaviour.OnEnable ()

Only occurs with  mid air and works no problem with Ground Plane...

Although with Ground Plane the model is Shakey then either flies off to oblivion and returns but them is not anchored...

Crazy... This needs to be made solid... I hope this will be corrected with next releases of both Unity full version 2018 and a new release of Vuforia with Unity...

Both the Mid Air and Ground Plane are very important to my client and industry I am working towards...

Please advise...

Thanks

Paul

paul@terrasame.com