I went to a village and the top of the well was dark in the corners and edges.
Seed: -8381672275982324226
Coordinates: /tp @s 202.03 71.91 1536.95 769.10 20.23
This also happens to random corner blocks around the world.
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Why crash the game?
Crashing the game causes part of the game to reset, and it should fix your lighting problem by causing the lighting to be re-calculated. But only crash it after you have done the first two things on the list.
Can someone check if this issue is still reproducible in MC 1.13-pre6?
Is visible the best with brightness moody and smooth lightning off. Not just a visual glitch, light level is actually 14.
Possibly related to MC-132283
Confirmed for 1.13.1.