Update on this issue:
We are aware that this issue is still present in the 1.11.0 update, but we do have a fix currently in the 1.12 beta.
Workaround:
As a workaround, adding additional lighting to the area can prevent spawners from spawning mobs, but every area in the room will need to be lit to 11 or higher.
Mobs will continue to spawn from,a spawner when torches are placed. Causing terrible lag.Beta 1.11
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Can you provide a screenshot or video of the set up please?

can we at lest keep this on hard mode 😃 or at lest 13-15 light level keeps the from spawning but ya it's broke in 1.11.0.3

I tested for this issue for a while but this only happens when there is one torch on the top side of the spawner with a poorly lit area. If surrounded by torches and the area is lit up, the spawner is completely disabled.

I did a little more testing
torches gives off light level of 14
problem: the spawner spawns with light level of 12 and under [https://imgur.com/CvMx6Pr
normal condition: higher than 7 would not spawn mobs
p.s. i might ask to keep this kinda nice for hard mode

I noticed this same issue when I was playing yesterday. I am on XB1 Bedrock Beta, Experimental Mode, Survival. The spawner always stopped when I put a single torch on it so I could tweak my space to make a more efficient grinder, in the past. Yesterday, I figured I'd try to convert the space from a zombie spawner to a drowned one. Placed a torch on the cage and immediately got a zombie (I assumed I timed it just right with the spawn tick). Then I had two more show up. So, I placed torches all around and underneath the cage, as well as four more along the walls of the space (well past the necessary light level needed to stop spawning). I spent the next few hours getting beaten up by zombies while attempting to change out my grinder build. Nearly lost my sword and all my gear before I walked away and did some other stuff. What worries me is that this might be a bug that will affect another spawner that I have a torch on from WAY before now. Hopefully, this will be resolved for normal difficulty (at least), because it's super frustrating at times.

Oh, I'm a dummy. I was using Java edition because of Mega_Spud's screenshot. I'll test this out right now.

Confirmed to produce this bug.

That's different... Usually I hear about the spawners breaking and the devs claiming they can't just write a code to reset them. My spawners spawn a few mobs, then stop and the spinning mob inside vanishes

What do you mean Theresa Mackillop? Can you show us?

@@unknown If you are talking about MCPE-36611, that is a different issue.
This issue is about mobs from the mob_spawner "block" spawning mobs in high light levels.
Please keep chat related to the reported bug.

Yes, that is the bug I was referring to. If someone would just FIX IT and the spawners they broke, I wouldn't have to keep bringing it up.
I'd never heard of a spawner still spawning when lit up, though

I understand your frustration, but KillerbeeNL is right. You must keep comment relevant to the post. Your comment won't help this bug or that one get fixed any faster. For now, let's all try to be useful.

I noticed that, too. At first I thought that I left the gate open and a zombie got loose, but it was closed and the mob spawned in a lit hallway next to where my spawn grinder is. If this isn't resolved, it's going to make things super difficult. On the upside, double piston extenders seem to work without issues in bedrock... So, maybe that's the trade off?

I found a torch pattern to stop them.... maybe a clue for a win 10 bedrock fix?
One torch on each side and top of the spawner, one torch on each wall directly across from the spawner, one torch on the floor directly under the wall torches, and one torch on the floor in each corner!

Had this problem in 1.11.0.7 (win 10, survival, normal difficulty, vanilla) with both cave spider and skeleton spawners. Also noticed a lot of cave spiders spawning outside of the spawner area, even in lit corridors. Some areas were more problematic than others, like a couple corners of the mineshaft spawning 9-10 spiders every few minutes.

I can confirm this too, i have a zombie spawner in my world and this needs to be fixed as it causes unbalance with regards to the difficulty in the game.
This bug is fixed in the latest beta version, and the fix will be included in a future update when that is ready for full release (no specific date can be given). We will leave this ticket open as a point of reference until the fix has been fully released.

Information to help you work around this bug in the meantime: You can disable the spawner by placing a block that emits light level 15 (glowstone, sea lantern, jack o'lantern, lantern, campfire, or powered redstone lamp), one on each of the 4 sides of the spawner. Additional light sources above, below, and elsewhere in the room are not necessary, nor do they prevent this bug.
Edit: Here's a picture of the minimum lighting that will stop the spawner. I built the room diamond shaped, but it will still work if your room is square because the spawner only spawns in the diamond shaped area anyway.
[media]
When trying to disable a captive mob spawner converted to a mob or XP farm, in survival mode you will likely have a large accumulation of the mobs to get through first. You should find it helpful to throw splash potions of healing II at them, and you get all that XP as a bonus!

How to enable such debug screen like the bedrock_lit_room.jpg as above?

You can't. That picture was added by Mega_Spud, who works for Mojang. The debug screen is only available in developer builds.

To add-on to the original issue, i have a mob spawner in a W10 Minecraft Realm, it worked perfectly fine until 1.14 came in, now it just wont work whether its lighten up or not

@unknown: This project (MCPE) is for the Bedrock editions of the game. 1.14 is the Java version. Please report your issue in the MC project.

A hotfix was just released and the changelog lists this bug as fixed.
https://feedback.minecraft.net/hc/en-us/articles/360027682131-Minecraft-1-11-1-Bedrock-