The shadow "bug" only affects Mac. Apple broke OpenGL horrifically in OS15.1 Point and Area light will preview totally blacked out. We simply can't fix what Apple broke in the OS at the Application level. To prevent scenes from loading totally blacked out the only thing we can do is disable hardware shadows on load. If you don't upgrade to OS 15 and never allow another Mac OS update you'll be fine. If you already updated send your appreciation to Apple for breaking OpenGL. Again this is Mac Only.