The bug
When blocks are placed in the world with the fill command, the sky light is not recalculated for the blocks below the placed blocks.
How to reproduce
Create a new superflat world
Go to 0, 0
Run
/fill 0 255 0 63 255 63 stoneCheck the sky light below the filled area
→ ❌ It is 15 when lower values should be expected
Linked issues
is duplicated by 8
MC-131961
fill command doesn't recalculate light levels
Resolved
MC-143153
Fill command does not update lighting.
Resolved
MC-143263
lighting bug
Resolved
MC-144033
Light levels does not update after replacing a large area of blocks with air using the /fill command
Resolved
MC-145145
Middle scale light update glitch
Resolved
relates to 2
Attachments
Comments 17
Seems to be happening in 19w04b in a map I'm working on in a void world. Filling in areas with hollow boxes of black_concrete and the inside is staying lit every here and there. Not the entire thing but not 100% sure on that.
Sometimes it will happen when you are in a enclosure space and rejoin the game, even if the enclosure space is not built with /fill command. Before you quit the game, there is not the skylight(it's normal), but if you rejoin the game, it will probably appear partial and weird skylight
@unknown: I wasn't able to reproduce with the same steps. The mobs that were there start to burn and no mobs continue to spawn. The F3 screen also shows that the server light is 15.
Our Minecraft server is currently running 1.14.2. I've been affected by this lighting bug for my witch farm. Only half of it is dark at the moment, despite putting a roof over the entirety of it. I loaded a backup of the world in 1.14.3 pre release 4 to make sure the farm would be fixed in the next update and the lighting bug still occurs. I have tried removing the roof of the farm and replacing it, but the lighting bug is still there. I attached a copy of my world as well as screenshots showing the bug.
Steps to reproduce:
Go to 1600, 60, 280
Use the /fill 1610 71 270 1565 71 315 air to remove the current roof
Use /fill 1610 71 270 1565 71 315 smooth_stone_slab to add a new roof
I did try the steps listed above to reproduce the bug and the bug didn't occur so I'm guessing this might have to do with updating a current world.
[media]
The initial roof was not made with the /fill command. I replaced the roof manually first without any luck. I then used the fill command with no luck. No other blocks were placed using the command.
Then you're having a different issue it seems. Follow the steps provided in the Moderator Notice in MC-142134 and see if this fixes your issue.
Fry
It looks like revert of this fix: MC-137903
EDIT: When you fill at 255 height - none of light update - not server, nor client. When I filled at 254 after that - server light updated, but client light did not.