Before the update ARView.session seemed to be accessible, but now after the update it is not.
The documentation says it should be there
So I very confused why I am getting an 'Use of unresolved identifier 'session'', since the update.
Can anyone tell me how to fix?
Change your run destination to an actual/generic device. This kind of build error suggests you're targetting Simulator, and RealityKit doesn't support the Simulator.
That was it!