Spawners randomly stop working

Is the world set to Caves & Cliffs experimental?

Yes

I play on a realm. Since the 1.17.30 update my skeleton spawner stops spawning skeleton after around 20 minutes running fine. Happened to me 3 times while decorating the room. I tried going far enough to unload that chunk (first i went 7 chunks away, second time i went 300+ blocks away) and it didn't spawn any skeletons. BUT after logging off and relogging it started spawning again (I did that twice). It simply stops spawning them after running fine for a while.

I'm also having issues with spawners not working on realms. For some reason they will spawn for a few mins then completely stop spawning. It might be a realm bug. The spawning room is completely dark with no lights and not glass. Im standing inside the spawning room and nothing spawns at all. Its kinda random when it works. I don't know how to reproduce it but ever since 1.17.30 officially released spawners just straight up bug out.

I am experiencing what seems to be the same issue in a non-experimental world that I created soon after the release of 1.17. It's a single-player survival world set to hard difficulty.

I have the same issue with spawners (not just skeletons) on realms. It will work for a little while then completely stop working out of nowehere. The room is completely dark, made almost entirely of tinted glass, and logging out and back in again doesn't seem to work. Unloading the chunks sometimes works? But man is it frustrating.

Confirmed with PS4/PS5 bedrock edition, world running on PS5.

World is not Experimental.

Difficultly is normal.

Version 1.17.30.

Skeleton spawner was setup on August 20th under 1.17.11, appeared to work fine, hard to fully know since had limited experience with it before the update to 1.17.30 on the 21st.

Since 1.17.30 randomly will work, if host is in overworld and goes to nether appears to break it, even if they return to overworld.

Have no other monster spawners to test if having same issue with.

Probably unrelated but adding, noticed with bee's that they weren't leaving the bee nest either. Didn't have bee hives to test with when noticed.

When the spawners stop working, does anything nearby stop working also? I am thinking that if it is an issue with block ticking, then things like crops or redstone in the same chunk might have problems.

Another possibility is that this could be due to to desyncing, where the player’s position server-side does not match where they appear to be. You might get random fall damage in connection with that.

I was upgrading the item sorter at my zombie farm, zombies had no issues spawning during. When I was done, I went up top and killed some zombies to test it out and they eventually just stopped coming. Threw some more items into the system from my inentory and they all went through correctly. All the members online at the time came to look and nothing spawned out of the spawner, but wild spawns elsewhere in the world occurred just fine although villagers were not restocking after several days one member had trouble growing some trees, though I think they may have been too close to his house. The realm eventually kicked everyone off and when we got back in, we were reverted to a point after the spawner stopped working, the items I had thrown into the item sorter from my inventory had been returned to me, but zombies started spawning at the spawner again

GoldenHelmet, in my case i have a trident killer (in the same chunk as the spawner) for killing the skeletons and it was running just fine all the times the spawner stopped working.

As for desyncing, at least I never took any random damage at all.

Resolving temporarily as Awaiting Response. Could someone please attach an affected world to this ticket?

PS4/PS5 bedrock edition, world running on PS5.

World is not Experimental.

Difficultly is normal.

Version 1.17.32.

Simulation Distance is set to 10, max that the PS5 was able to set to.

Seed: -1714017794

Skeleton spawner Location: 1957, 22, -601

Skeleton spawner when working also only spawns like 3 at a time, with nearly max spawner wait. In the past noticed that spawners can sometimes pop out mobs, but with this, have a bubble column/drop chute, so can easily kill them and have to wait a bit for more to come in every time.

Also noticed when we went to the End Portal at -1100, 212 on the map, the silverfish spawner only spawned 1 silverfish, rather than the waves it normally does, destroyed that so unable to test with it further.

Had encountered several blaze spawners and were working, however only spent a little time with them, it seemed like they only spawned 1 at a time, and with nearly max spawner wait also.

Cave Spider spawners when encountered in a mineshaft also only had a few around it, and none spawned in time to torch it up.

Spawners work for a bit, but if leave the area have a chance for it to not work, haven't noticed any issues with crops not growing in any of the farms we have for it.

Somebody please confirm that this problem occurs with no resource packs active, in either the world or Global Resources.

We are still waiting for someone to attach an affected world, please. We will probably not be able to solve this without one. If you have such a world but it's too large to upload here, you can upload it to a file sharing cloud service such as OneDrive.

In order to get an affected world file to upload, I attempted to replicate this issue with no resource packs active and was not able to.

I tested on an Experimental - Holiday Creator Features enabled world, at a blaze spawner in the nether. The spawner originally worked fine even though I had resource packs on, and two friends joined my world who also had resource packs on, and it continued to work fine. The moment one of them entered the nether to join me, the spawner stopped working. 

We then tested with no resource packs. Spawner was working, friend joined, entered the nether (no resource packs on) and the spawner continued to work.

We then tested me again having no resource packs. Friend with resource packs on joined, spawner was fine. They entered the nether and immediately the spawner stopped working.

Players on a server I play on describe the experience that the spawners work when there are no other or few people on in the mornings, but as time passes and people start joining, the spawners eventually stop working. Another player described the spawner as working fine but it would stop as people joined/left the server. 

The realm I play on has a texture pack enabled. As the previous comment mentioned, I too have noticed the spawners only stopped while other people were on and currently suspect they might even stop working when another player is near another spawner, but haven’t had a chance to properly test that theory yet, only while other players were in areas with few mobs, the spawner consistently worked for two hours. I asked a friend who plays with no resource packs at all and he says he has no issues with spawners suddenly not working

Thank you for the additional information. Since it seems to be triggered in multiplayer only, and only with players in the same dimension, could someone test if the distance between players affects it? We have another report of simulation around one realm player being impacted by whether their chunks are within render distance of another player (REALMS-9266).

Also, after a spawner breaks, does it resume working if other players leave the realm, so only the player near the spawner is in the world?

I play on Minecraft Realms 1.17.1. My zombie spawner stops working after an extended period of time. No other users are on and I'm AFK on hard mode. This has been a farm a long time and nothing has changed regarding lighting etc. It will always stop working overnight. The zombie avatar in the spawner does vary speed but never generates mobs. I have seen the zombie dead still as well.

The spawner will resume if I kill myself and walk back into proximity. Same with logging off and on. I have walked a long way from the spawner and back but the spawner doesn't not start functioning again.

I asked another member of the realm to help me test the spawners and had him sit at one of the zombie spawners, he sat at around -20, 30, 312. I started at the spider spawner, around -55, 58, 54 and we sat for a while watching and they both continued working. I went over to the same dpawner he was at and watched, it continued working. After another bit of waiting snd nothing happening, I went through the nether to another zombie spawner, around 16, 50, 6339, and both continued to work. After some more watching and waiting, I then went back into the nether and back to the first zombie spawner where the other member was at and by the time it was in view, I saw no zombies in the kill chamber and there were no new ones spawning in, the spider spawner had also stopped, but the farther zombie spawner continued spawning properly. Another thing we noted was we could still hear zombie sounds even though the area is so lit that the only zombies nearby should be only coming from the spawner. We attempted to see if they would start working again by both logging out of the realm for a moment and going back in. I went back in first while he had trouble connecting for a bit and they did not resume spawning. The realm owner then logged on and I informed him of our testing and we all went back to our projects, though I occasionally went back to check the spawners and they did not start working again at any point in the night. Now that it is the next day and I’m the only person online, they are back to working properly.

This happens in my single player world also. When it does passive mobs like cats and rabbits also disappear. I’m playing in IOS, haven’t tried Java yet.

@unknown: Thank you for the highly detailed account. Although it doesn't help me as a staff member, I believe having all those details will be very helpful to the developers. Just one thing though: You said this Realm has a texture pack enabled. Can you tell us which one, and can you find out what the world seed is? With that information we might be able to reproduce the problem, and then we could turn it over to the devs.

The texture pack is pure bdcraft and ui, the world seed is-1214045649

My friends and I are realizing how this glitch is happening.  Whenever we go to another dimension, even one of us, the spawners stop working.  The blaze spawners in the nether don't work either, we have been relying on natural spawns.

Definitely having this issue on a long term world with a double skelly spawners next to each other.  This is on a BDS hosted by apexhosting.  I am working on getting a copy of the world here but it is almost 2.5 GB's right now.  i just noticed today but haven't been on much.  We are on 1.17.34.02 BDS.  Vanilla with just two custom texture packs.  One for rain by FoxyNoTail and one we made for totems.  It has been working for about a year with no issues before this.  We had 3 members on at the spawners with no one else around and no spawns.  Also nothing when the other 2 were elsewhere and I was at them.  The spawners were "spinning" properly and all but nothing spawning.  Of course we have water underneath flowing so not sure if something was changed with that or something???

I'm having this same issue on a realm. Mobs are not spawning from spawner at all.

Steps to Reproduce:
1. Be near a working spawner (on a realm) 
2. go into a nearby portal to nether. (Note that traveling 100s of blocks in the overworld doesn't seem to cause an issue)
3. return to overworld near spawner.
4. spawner stops spawning mobs.

Observed Results:

Light levels are 0,
There is a 7x7x7 space around the mob spawner
I am within 10 blocks.
The mob inside just spins but doesn't spawn a mob (waiting 30+ min)  

Expected Results:

When light level is 0 and within range of spawner, expected mobs of the type inside the spawner to appear within a few minuets. 

Thanks for reporting this bug👍 I usually play on two different worlds both from my PC (Minecraft Win10 Edition). One is my long term local world hosted on my pc from within Minecraft without BDS. The other is hosted by someone else using BDS. Both worlds have been affected by this bug which renders spawners useless after updating to 1.17.3.

The easiest way to replicate this bug is to have two players in the overworld.

Step 1) Stand Player 1 within range of a working spawner. 

Step 2) Player 2 enters any nether portal from the overworld.

Outcome) Spawner at the first players position will no longer spawn mobs.

On a BDS hosted word with many players, if your spawners stops working you can relog to "fix" this temporarily or at least until another player enters a portal. On this world other players have reported that another player being within range of a spawner has been enough to stop theirs from working. 

If you are locally hosting your world then this "fix" does not apply and the spawner will remain inactive until the host relogs, kicking every player.

This is a big issue that affects all multiplayer game modes as well as single player worlds. 

I think everyone can agree that one active spawner per world is definitely going to have a negative effect on gameplay and needs to be fixed asap. 

BDS-15605 seems to be the same problem. Please up-vote so these issues get fixed!

Thank you 😃

Thank you for your time and effort @unknown . With this world you should also be able to confirm that this problem is not just multiplayer related.

After my original post I continued testing and found that with just one player logged in the exact same behavior could be observed.

Step 1) Load world and confirm the spawner is working.

Step 2) Travel to the nether & back.

Step 3) Move within activation range of the spawner & observe.

Observed Results: The spawner stops spawning new mobs

Expected Results: The spawner's spawn activity is unaffected.

I'm not sure if this info changes how things get reported but it is worth mentioning.

Thank you to everyone who has commented & voted 👍

@unknown: Thanks for the update. I tested again, by myself, and confirmed what you said. It also gave me an opportunity to try some other experiments to try and find more information, which I've added to the description.

By the way, asking for votes the way you've done it hasn't crossed the line, but please be cautious about doing that. In general, we look down on vote shopping, as some people have used it as a way to get priority for a bug that especially affects them but not very many others. In this case you're ok because only people who have this problem will read your vote request, and they're almost certainly affected so voting is what they should do. But somebody else recently offered to trade votes, and that's gaming the system. Besides, we stress that the bug tracker is not a discussion board, and comments should only be used to provide new information to the developers.

Hi, I have a Zombie Spawner under a villager trading hall. The spawner is at Y=17 and I play on a server. At least 5 individual players load the zombie spawner. I has stopped working three times. The first and second times there was no zombie in the middle and It started working after a server restart. The third time the zombie is in the spawner but it will not spawn mobs, even after a server restart.

This bug also affect 1.17.40.6 Windows 10 Edition.  Single player, LAN Multiplayer worlds & BDS hosted servers.

Steps to reproduce, observed and expected results as per @unknown  instructions.

A newly generated world has been included.

This also affects the Xbox Realm Version aswell. And we reloaded the world and it worked for a little then stopped working. I hope they find a fix for Xbox because I can't download the zip for Xbox.

Adding this comment as it might help with some theories about dimensional travel.

PS4 - 1.17.41.  This bug might have occurred prior to .41 but this is a world with lots of play time and we don't visit the villagers/zombie spawner as much anymore.  In our world set-up, we always use the nether to get from our main base to the zombie spawner/trading hall combo.

Typically play split screen with 2 players, and sometimes with two others joined via Android (local WiFi).  This bug was first noticed during a play session with two split screen players on the PS4, and one connected via Android.  "Player 2" and Android user both experienced this bug when first encountered.  At that time, P2 opened up the spawning chamber to check for light levels and visually verify there were no spawns that might be missed through the tinted glass.  No spawns for approx 10 min.

Last night (split screen, 2 players, no others connected via WiFi) I had reason to head to the trading hall from our main base (nether travel) and upon reentry into the overworld, the zombie spawner was working as normal (spawns and rates).  I made some trades and killed some zombies then left to the main base (nether travel).  A short time later (10 min), I returned to the same hall/spawner (nether travel).  Made some more trades and afk'ed at the kill chamber for about 5 min while letting the dog out. Upon returning to the game, there were no zombies.  

I have not checked any other spawners in our world to verify functionality.  I have not yet seen the spawner work then stop while the chunk is loaded, and I have not seen a broken spawner magically start working while the chunk is loaded.

Unfortunately, I cannot provide the world off the PS4, but here are some details:

Seed: -1739651205

World Creation: 1.16, but I can't verify the exact version.

Main base overworld portal: -190, 65, -243

Z Spawner/Trading Hall overworld portal: -277, 29, -116

(Base and Spawner are not within sim distance as we have never entered the spawner with zombies already in the kill chamber)

We have no resource packs loaded.

This is happening in my realm with double zombie spawners. Spawners are located at border of 1.16 and 1.17 generated chunks.
Seed = -1337710146
Coords: 1459, 22 ,1835 and 1448, 17, 1834 (Y coords are approximate)

I afk here within 16 blocks of both spawners, and eventually, all zombies stop generating from both spawners.

I JUST found and set up a zombie spawner farm, while I was making it the zombie in the spawnser disappeared. I left the chunk to let it reload and it still didn't work after I returned. Kinda sucks but maybe after it  gets resarted it'll fix it? Either way wanted to add my voice and example to the pile.

This is happening on two different completely separate realms I am currently playing in. One of them has experimental gameplay the other does not. The spawners will be working fine for a while then just suddenly stop, usually when there are 3 or more people on and/or people going in and out of a nether portal.  Switching to peaceful then back to normal or hard does not resolve the issue. Only thing we have found that work to get it working again is for all members to log off and stay off for a period of time (not sure exactly how long but longer then 5 minutes).

This happened to me also. I run a BDS on my pc. And now I upgraded from 1.17 to 1.18 the skeleton spawner is empty (it wasn't when I discovered it in 1.17).
I can provide the world if needed.

There is a different bug that causes spawners to generate with no data, so they always appear empty and never spawn anything: see MCPE-138291.

I play on a server. This issue is still occurring in 1.18.  While AFK at a spawner it will work for a few minutes and then totally stops working. I honestly have no idea how to re-create the issue. I just know that spawners are working one minute and not the next. It is very frustrating.

same here

i have a bedrock server 1.18

my zombie spawner stopped after some while, no zombies spawned.

I have the same problem with a skellie spawner.  Have it in complete darkness and have tested various player distances but not getting spawns.  Any help or advice to fix gratefully received

I noticed that spawners now give off light, is that preventing spawns? 

Please do not add "me too" comments. To register yourself as another affected user, use the "Vote for this issue" link. Also, note that a fix for this issue has been applied to the 1.18.10 Beta, which means it should be including in the 1.18.10 retail release. Therefore, we don't need any additional information unless there's a problem with the fix.

@unknown: Spawners don't give off light. The flames that appear on an active spawner are merely aesthetic. Also, unlike general monster spawning, a spawner can spawn mobs at light levels 4 and below.

I don't know if this is part of the bug or it's own thing, I'm having the same issue happen of it just not running, but sometimes when it's not working it still has the floating skeleton inside it spinning around and sometimes there's nothing in it, and then it also seemed to have some lighting updating issues around it that didn't go away until the chunk reloaded. Playing on a realm in bedrock 1.18

Reply from @unknown: the lighting issues are tracked at MCPE-145828.

I think I am also experiencing this in some way.

I play on PS4 (Realms if it matters) and up till yesterday when a friend (PS5) was with me in the world the Zombie spawner worked fine. For some reason a water elevater with signs did not work as before 1.18, so we decided to visit the nether for some soul sand.
After we returned he left the server and I stayed alone, fixed the farm and now the spawner does not work anymore.

At first there weren't even flames in the spawner and I already feared to have broken it somehow. After logging out and back in it shows the flame sprites again and also a very fast spinning zombie in the spawner block. But no spawns at all. Obviously complete darkness. There shouldn't be too many dark caves around either since it's almost directly underneath our village and we have scouted and lit the caves pretty thouroughly by now.

I don't know what triggered this bug. Was it my friend leaving? (I am the main owner of the realm) Was it our first trip to the nether? Was it me switching the water elevater to soul sand? (didn't touch anything else)

I will try distancing myself from it for a few hundret blocks today and also if him being on the server makes a difference.

I have also experienced this issue (PS4 realm, world created after 1.18). It wasn't working at all when I logged in today. As opposed to working, and then stopping.

Had all members log out for 5 minutes (timed). This did not work.

Had them log out for 10 minutes (also timed). This did work.

So there's some point between 5 & 10 minutes with no users on the realm that will get whatever is breaking these to reset.

I'm on PC experiencing this same issue on my multiplayer server. Usually stopping & restarting the server makes them start to spawn again, but eventually it stops working. The past week its always been 10 minutes maximum that it would spawn before stopping; after testing again last night with the 1.18.10 update, it was working for a few hours straight and then stopped again. Leaving the area / de-loading the chunk and returning does not fix it for me. Going through portals & back also has no effect on the issue.

Unless you have actually new information for the devs, we would rather you upvote the issue than leave a comment. This is a kind of vaguely defined bug and some of the recent comments might contain something unique, so I've left them, but please don't comment just to say "me too". Upvoting accomplishes that better than commenting.

You can read more about our comment policy here.

Gonna make this short but brand new realms, ps4, right after 1.18 no zombies spawning in my xp mob farm. Completely dark.

Having this issue on 1.18 up to 1.18.2

Win 10 and android. On Realms.

Spawner worked for a few minutes and then stops. Log out and in and it worked. Next day it didn't  work even if logged out. Now have two spawners, zombie and spider that won't work for days now. And other people on the realm say same thing as well as another that says there is nothing in their spawners.

I've also made sure my farm I was making was completely dark. But the first day I was making it. I closed it off and it was still lit up inside even though there was no light source at all. Logged out and came back next day and it was completely dark in there.

I've seen this ssue with the light not going away after blocking the area off a few times now.

I have a Bedrock realm, with Minecraft 1.18.2 on my PS4. I found a double spawner: skeletons and spiders. Before the upgrade to 1.18, these spawned just fine, most of the time. Now they've completely stopped. Running in survival, hard mode. Rebooted the PS4 and the realm several times. Went away from the spawner for a couple of days. Getting plenty of mobs elsewhere. Just not from any spawners. I'm AFK-ing behind glass panes, alternating with a minecart on powered rails, with both half block and full block openings, within 7 blocks of the spawners. I can ride or stand around for an hour without a single mob spawning.

Still happening on our 1.18.2 hard survival bedrock server with Xbox, PS and PC players. No spawners in the overworld are working, they worked once when first found, but nothing since lighting them up to make a spawning room, even after torches are removed. Blaze spawners do not seem to be affected. Multiple people or just one being online does not affect this, and it is not a mob cap issue since we culled everything on the server to check. We have rebooted the server, and tried multiple fixes but nothing has worked.

We have found 15 spawners, zombie, spider, cave spider and skeleton, and not one of them works after they have been lit up and had the torches removed. It seems like the game is not registering that the torches have been removed and light level is 0, so mobs are not spawning. 

Playing windows 10 on a realm. I have a skeleton spawner that just quit working, at one point there wasn't even a skeleton in the spawner cage, however, it came back after reloading the world. Spawner still doesn't spawn. I've reloaded the game, gone to the nether, slept, left the chunck multiple times, lit and delit the area. Nothing seems to be working. My friend has a zombie spawner about 1000 blocks away, it is still working as normal. 

Minecraft 1.18.2 hotfix Spawner stopped working when 1.18 was released 0 light level one day it works after awhile it stops nothing spawns for multiple in real life days I surrounded the entire thing in tinted glass so it's not the light level

Having this issue as of the 1.18.2 hotdix, I have a quad Spawner, 2 cave spider, a spider and a skeleton, which work for around 5-10 minutes after they activate, but then I have to reload the world for them to work again. They also don’t deactivate at the same time, sometimes the skeleton deactivates first, sometimes it’s the spider, other times both cave spiders deactivate before either of the spider or skeleton. It’s very strange, and very annoying.

I am also having this problem on Xbox One, rev 1.18.  Spawners work fine while I am logged into the world alone.  As soon as another user logs in, the spawners stop spawning.  This occurs even when we stand right next to each other in the kill chamber.  This happens in a double zombie Spawner room, a single zombie Spawner room, and a skeleton Spawner room.  

1.18.2 hotfix, After some testing the spawners stop working when there's multiple people online, it works perfectly fine when no one online once people started joining it stopped working this also isn't the only reason as stated before it just completely stops even when no one's on for a very very long time before more start to spawn

Additional info:  Spawner activity continues as long as I remain logged in as a single user.  I’ve let it run for hours and it keeps generating zombies.  As soon as someone joins as a second player, the Spawner will stop working.  This happens both on local Xbox multiplayer as well as a Win10 laptop Bedrock login to the same world, as an additional player.  When the extra players log out, the Spawner will not restart normal function.  I have to exit the world.  However, if I log back into the world, the Spawner then begins to function again.  I do not have to fully quit the Minecraft program to restart the Spawner operation, just exit the world and log back in as a single player.  

1.18.2 bedrock server- in addition to my other comment about not getting mob spawns from spawners, we are now finding empty spawn cages. The others we found had the fire and the spinning mob, yesterday we found two new spawners and they were just empty. I attached a photo of one I found below my base  

On Xbox One, recently switched over to creative to recover from all the bugs affecting our world.  Noticed the Spawners began to work for me, even when multiple people were logged into the game with me.  I set myself as the only player in Creative mode.  Everyone else was in Survival.  Hope this adds a clue to where the code could be disabling Spawners for survival but reenabling them when the main account is in Creative.  

I am having the same issue, however it is now happening even when I am alone on the server.  Sometimes I have to run around to different spawners and only 1 of them will be working.  I have seen it where the mob spawners was totally empty and where it is lit and has a spinning mob but does not spawn anything.

Just my two cents on this issue:

a) I'm playing on a Linux BDS. To have the one spawner (Skeletons) I experience this problem with get back to working order I have to restart the BDS, relogging does not fix the problem.

b) The only other spawner I currently have is a cave spider spawner, which is NOT effected by this problem, even though I have to use the Nether to get to the spawner.

K.

Just ran into the same issue on Realms.   Although with Realms, you can't just restart the world.   I had to download the world to my PC and then reupload it - which forced a restart.   I'm guessing I could probably have restored a backup as well but I would have lost some changes if I had done that.

Reply from @unknown:
If you have Realms+ (10-player subscription), something else you might want to try is activating a different slot temporarily, then reactivating the original. You probably wouldn't even have to open the second world for this to work.

On Realms+, another workaround that sometimes works is to have the player in the spawner chunks log out and back in. That sometimes performs a temporary fix. Noticed that this bug seems to occur more often in chunk areas where spawners are close enough to be set up as a double farm.

Sometimes the logging out/in trick only causes the spawn cages to re-ignite, showing the spinning mob inside and the flames, but still does not generate spawns.

I started having this issue on realms about a week ago. It only happens to me if there is more than one person on the realm. It is only affecting my zombie and skeleton spawners, no issues with the blaze or spider so far.

I think this is the right issue. I'm playing Bedrock 1.19.2, and a zombie spawner I found just... quit spawning anything. This is a local game, not Realms or anything. All stock, nothing special (no experimental). I built an xp farm around it and used that successfully for a few hours, and when I got back on today it just wouldn't spawn any zombies.

Tried leaving the area and returning, restarting minecraft, fiddling with the difficulty levels, nothing.

I agree that your description of your problem sounds like a good match with this bug report. However, you may have noticed that a fix for this issue was implemented back in February, in 1.18. At least dozens of people with the problem were notified at the time, yet none of them objected to us closing the ticket as resolved and fixed. This is normally good evidence that the fix was successful, so now we have the question of why you seem to be the only one having this problem. Is it a reversion, a new problem that's coincidentally very similar, or perhaps something unique to your device? Please help us narrow down the problem by answering the following questions:

1. What platform are you playing on?

2. When was this world created (either game version or date is fine)?

3. When did you first discover the spawner?

4. How long ago did you build the XP farm around it?

5. Does the issue happen sporadically or every time you load the world now?

6. Can you reproduce the issue with zero resource and behavior packs installed (including in Global Resources)?

7. The action of a mob spawner is conditional on several things, such as the relative position of the player, the number of mobs of that type within a certain range of the spawner, and (if I'm not mistaken) mob caps. There's a list of them in the Spawner wiki article. Have you checked all these conditions?

Thanks for responding so quickly.

1. Windows 10 PC

2. Created last weekend, July 1st or 2nd? v1.19.2

3. First discovered the spawner on 7/4 or 7/5.

4. Just finished the xp farm on 7/6

5. It happens every time I load the world. Since I noticed the issue yesterday afternoon (7/7) the spawner has not worked at all, no matter how many times I've restarted MC or changed difficulty settings.

6. This is a stock bedrock game. The only Resource/Behavior packs are Minecraft Textures (Global) and the Default behavior pack, which afaik can't be turned off.

7. I have checked all the conditions. Like I said before, it WAS working under exactly the same set of conditions previously.

Okay, I just noticed something weird. I went inside the spawning chamber and closed the (spruce) door behind me, and noticed that the light level doesn't change with the door closed. It's acting like the door is transparent with regard to light transmission.

When I broke the door and replaced it with dirt blocks, the light level dropped and they began spawning again.

I'm mystified by this, because I've always built xp farms this way, leaving a door for access.

If I leave the door and move the light source further away from the door, they do spawn normally.

So... I think it was just a lighting issue. But I could have sworn a spruce door would block that light.

I think the only thing that changed (that caused it to break) was that I was using glow vines for light, and the one closest to the door grew and spawned a new berry.

I also thought that doors were completely opaque, but the wiki says they're "partially transparent" and my experiments confirm it. So apparently you've solved your problem. You can probably just move the glowberry vine a few blocks (maximum of 4 needed) away from the door and eliminate the problem.

Yep, that did it. Even after I bonemealed the vine to get some berries back, the spawner works fine. It was just that little bit too close before. Thanks!