I am playing minecraft 1.8 vanilla while creating a mob spawning room I have used commands to fill the required blocks. the room seems to be complete but with one issue. you can see the light level 15 in the snapshot. However the room is totally concealed.

When I fill the blocks manually the light level goes down to 0 as expected.

so by using fill command why does the light level does not fall to 0 enter image description here enter image description here enter image description here enter image description here

  • 2
    Looks like a bug. You should report it on the mojang website. Commented Dec 20, 2015 at 11:36
  • I agree with angus; it's probably a bug. A temporary fix would be to use commands for all sides but one, and fill that one in manually.
    – rivermont
    Commented Dec 20, 2015 at 13:40
  • I suppose that means /fill commands don't cause lighting updates. You could try spawning a FallingSand entity and having it fall into a spot on the floor (setblock X Y Z air and then summon FallingSand X Y Z {Block:"minecraft:your_block_here", Damage:?, Time:1}) Commented Dec 21, 2015 at 0:34

1 Answer 1


This is a common bug that happens to me all the time.

I have a few way of fixing these:

Firstly, placing blocks (in particluar light emitting blocks) around the glitched light patches should fix the problem.

Secondly, if placing blocks doesn't work, try reloading minecraft and the world. Another thing I have found useful is to set your render distance to 2, then press back to game... and then put your render distance back up to 10-16 to fix.

Thirdly, if that doesn't work you can use McEdit to fix the glitched light blocks

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .