I was working on a GearVR project at the office on my Win64 workstation running the latest release of Unity (Non-Beta). I decided to try the beta at home on my Macbook Pro, and compiled my project in 5.4 b22. Immediately I experienced this HORRIBLE flicker of the brightness when running anything at all. Doesn't seem to be having to do with anything in the scene, this is a total flicker of the phone (Galaxy Note 5). Looks to be a terrible bug having to do with Forward Rendering mode set in build settings. Setting to deferred fixed the flickering issue.