How to Fix Chunk Loading and Lighting Glitches with Starlight

Why lighting looks wrong

Starlight replaces vanilla's lighting engine, so most lighting bugs come from stale data in an existing world rather than the mod itself. If you see dark patches indoors, light that does not update when you place or break blocks, or chunks that stay black at the edges, the fix is usually to force the affected area to reload.

Steps to clear lighting glitches

1. Walk or fly away from the affected area until those chunks unload, then return. This forces Starlight to recompute lighting for them.

2. If that fails, save and quit to the title screen and reload the world. A full reload recalculates lighting on load.

3. For persistent black chunks at the world border or in newly generated terrain, move far enough that the chunks fully unload, then come back — do not just stand still.

4. Place and break a light source (like a torch) in the dark spot. This triggers a lighting update in that block and often clears a stuck patch.

Chunk loading stutter

If chunks pop in slowly or the game hitches while flying, that is chunk generation and loading, not lighting. Lower your Render Distance so fewer chunks load at once, and lower Simulation Distance so fewer chunks tick. Avoid sprint-flying through unexplored terrain at high speed; let chunks load behind you. If stutter only happens near large redstone or mob farms, the cause is entity/tick load, so reduce Simulation Distance rather than Render Distance.