When a projector is on, only the projection is rendered. The rest of the world is pitch black

[TheFizio]

Except particles, fluids, my hand, the item being held and the wireless extension crystal, everything else is pitch black whenever a projector is off, as if rendering is switched over to the projection

[SmileycorpMC]

This usually happens if you have optifine or stellar sky installed, (if you have either of those) as both mods stop it from rendering properly.