DeeBusyBee

Disappointed to not see this bug NOT listed as being fixed in the Beta 1.8.0.8 Changelog. Saw comment above by CompactVoid, perhaps this has been fixed in Beta 1.7.0.2? (also happy to see many bugs being fixed in betas  - good work Mojang)

I hope this is fixed soon, especially with stray cats now spawning in villages (in above beta). This problem has been happening for so long.  I've got dogs sitting sentinel all over my base and they are waay overdue for walkies now.

I know violine and have contributed to bug reports on here before!  I put that here for two reasons:
1) to show the community has embraced storing xp in furnaces as an feature and improvement to the game that came with 1.13.
2) If XP could be stored in containers in stacks as an item that would solve unlimited xp being released at once from a furnace.  It would add a new dimension to many xp farms.  It probably requires a lot of coding but the technical players would embrace that.

I will delete the above and this comment if you think it's not relevant at all to this bug report and clouds the issue.

SKOOT4life added the below suggestion to a suggestion on r/minecraftsuggestions "Make brewing give XP like smelting"

"XP orbs can be an object of their own. These cant be used at all, and are just objects limited to inventories and storage. However when combining a set amount of them with a glass bottle a bottle'o'enchanting can be made. The reasoning for this is that when things are smelted and then extracted with a hopper, you dont get the xp from them. So the furnaces can release xp orb items into the hoppers allowing you to collect the xp later on and use it."

Yes, violine, I understand as it is, a large amount of experience released at once could crash the game.  Perhaps, like Xisuma said (in the top video linked there), they could limit the XP a furnace can store so it wouldn't crash a server or lag out.  It'd be good if that experience limit amount would equal. at least. 30 levels, if possible. It'd be great to keep this feature in the game. 
(Another use is, Xisuma has cleverly made a community furnace in Hermitcraft Season 6, charging hermits to smelt there while storing the experience for his use. lol)

If not a limit on the XP storage, perhaps there are other another ways to reduce the experience_orb entities released from a furnace to prevent crashes?

FYI I hope the furnaces storing xp feature can be kept.  In survival mode, it will encourage autosmelting without wasting XP, much better than manual smelting and collecting all the time.   Also it allows creations like these:

Further to the video linked above, Xisumavoid has tested and made some inventions:

Minecraft 1.13 Furnace XP Farm - https://www.youtube.com/watch?v=UgRUYmaYDlE Sep 9, 2018
(demonstrating it is possible to connect a furnace array to automated farms making a slow AFK XP farm, also demonstrating duration of smelting of different items required to reach 30 levels.

Minecraft 1.13 Instant Item Repair System - https://www.youtube.com/watch?v=uskkb72uIkk Sep 16, 2018
Contraption limiting amounts that get smelted so XP amount matches XP required to repair different items using a redstone counting system.

Minecraft 1.13 XP Storage Silo Tutorial - https://www.youtube.com/watch?v=8bdj_Uk3L_0&feature=youtu.be  Sep 22, 2018
Simplification of above item repair system using an autosmelter array.  Player can manually place filler items to set and limit the number of items smelted and the XP produced.

To help solve this bug:

• I could attempt to capture video proof of this bug, and link to Youtube,

• Or submit my survival world (55Gb) for testing (my base is located just across stream from the world spawn point).  You can get a look at my base in this introduction to my survival world video: https://www.youtube.com/watch?v=xUgn1y0L-sk

It happened again, this time in Bedrock 1.6.1.  I saved and exited the same survival world as described above (multi-level base dug into a large extreme hill). 
This time, I saved in the top of base Nether tower and spawned on top of it.

Saved player location: 297, 98, -4,
Spawned player location: 297, 104, -4,

(EDITED to fix formatting)

It happened againin Bedrock 1.6 on Windows 10 when I saved in the same xp farm sweet spot (as above). 
I saved the game with my player located at 286, 66, -2.
I spawned this time, (not inside my XP Farm phew, but ontop of it), at around 286, 92, -2.

I'm not sure which of these duplicate bug reports to add to.  My cliff house is inside a tall hill is similar to Troy Parry's.  The main part has at multiple levels dug out with a floor/ceiling between them.  There are more than three levels at certain points, if you count the mines down a stairway going back and below.   An indoor farm area stretches back as the only floor in that area, with an XP farm built above it with a drop chute of 21 blocks dropping into the farm area for XP 'collection'.

Many times I've respawned on opening after saving, with my character located a floor level above where I had saved the game.  As in the next dug out level above where I'd saved.

1. Once, I saved located in my bedroom (middle floor of three floors) and spawned in the room a floor above that.

1. Another time I was in my top floor brewery and spawned on level above that which is on top of the cliff.

1. Twice, I'd saved the game standing at a certain spot, in my farm area below a corner of spawning area of the XP farm and terrifyingly spawned at the next level above, inside my mob spawner area of my xp farm!! 😞 Spawning in the dark with mobs around me.

Where I stood while saving is the 'sweet spot' roughly 20 blocks below my mob spawner space and below one of it's corners.  When I stand there I seem to get more drops from the xp farm (?they detect me and fall off my 8x8 spawning platforms into 2 channel water drop best?)

• Where I saved the game (xp farm sweet spot): 286, 66, -2. 

• Where I spawned inside XP farm: 286, 88, 4
  (could be a few blocks off - I was distracted fighting spiders in the dark!)

Understandingly, I won't be saving the game while standing under the xp farm again until this bug is fixed! 🙂

This occurred most recently on 1.5.2, Bedrock Edition (windows 10) and on earlier versions before that.

(The usual place I save is located in my main front living room area.  I've never respawned above that, strangely.  There is a room above that but no other caves above that (I know there are no caves as I started the world as an 'old' world type, so 256 x 256 area around worldspawn (where I made my base) had no caves generated (useful when making the xp farm).  Later I converted it to infinite and the rest of the world generated as normal.

It only seems to happen at some locations in my base, intermittently.

EDITED as smileys didn't go through.

There's still lag when opening a shipwreck map chest (just the map chest).  I added some more info re: this to a bug report already marked as duplicate as above: https://bugs.mojang.com/browse/MC-133651
Is it always to be expected to have lag on a server for it to generate the treasure maps upon opening the chest?  (and also in a singleplayer world?)

Video Proof of lag in map chest generation on a current 1.13 server on youtube:

Hermitcraft VI - Nature Health Organisation & Ninja Grian - Let's play Minecraft 1.13 - Episode 6
around 33:24 minutes (link below to exact moment). 

https://www.youtube.com/watch?v=7SHFXtvB-KI&t=33m24s

(Docm77 opens a map chest in a shipwreck and the first time it is empty. He tries clicking again a few times and on the third right click swims away.  After a five second or so delay, the open chest noise happens and populated chest inventory appears on his screen, including treasure map). 

Adding more info to the above.  Just tried about 10 more shipwreck chests in Creative..  Only one map chest contents populated slowly after I'd opened the chest.  None were empty on first opening.  Only one I opened seemed empty then populated while I had it open.  The other map chests may have populated as I opened them, fast enough I didn't notice. Every other kind of chest seemed pre-populated.
Found two teasures too using the maps, and they were all within the red cross on the map, though not in the centre of the cross, more on the edges (one north west and one south west of the centre of the x)

I also found map chests appearing empty upon first opening for me in creative on 1.13 opened to lan on my survival world.  I wonder if they are generating contents after being opened or there's a bug in generating the map perhaps. 

I wrote about it on this bug report: https://bugs.mojang.com/browse/MC-133651?jql=project%20%3D%20MC%20AND%20text%20~%20%22shipwreck%20chest%22

Not sure if I should have made a new bug report, just adding info to this one.

In creative mode, Java 1.13 edition, shipwreck map chests (which contains a treasure map) appears empty on first opening.  The other chests in shipwrecks have populated items before opening, and don't have this problem. 
Map chests appears empty when I first open it.  When close and open it for a second time, it appears empty for a few seconds then as I watch, the treasure map and items populate!
 
Background info: My new survival world, i5-6400 pc with 8gb ram, GTX 1060, running Java 64 bit (build 1.8.0_181-b13)  render distance 16 chunks.  I opened my game to lan, enabled cheats, changed mode to creative.  Fying around scouting, checking shipwrecks.  Making sure chunk seems loaded before going into them. This occurred in treasure chests in two different shipwrecks.  (You may know me from some bedrock bug reports but I bought Java version now too 😉

Thanks Morgwenna for reporting and linking to the other bug report.  I'm the one who was writing on 34737 too.  Just put a quick video on youtube demonstrating the problem:  https://youtu.be/DxHeT--rfMM

Easier to demonstrate than describe.  It's taken me a while to figure it out more and remember how it used to be. 

Used to be able to keep holding and adding to a stack you just bought and trade over and over again until:

• you ran out of stuff,

• or the villager didn't want to buy any more of the item.

(The items you just bought didn't automatically go to your inventory but they accumulated floating (in your hand?) above the Trading UI.  You could keep trading and adding to those and them put them away later.)  Is that how you remember it too Morgwenna?  (excuse me flu is interfering with thinking!)

Just made a video demonstrating the ?bug and included sensational crash to desktop at the end, when I tried to buy a second enchanted shovel before putting the first one in my inventory.  It's done that a few times..  Pretty sure that happened selling carrots once so it wasn't just for buying enchanted items.

I think that if you didn't have room in your inventory before and now, the bought items would be dropped items.  If you were quick you could pick them up, or If you were very unlucky a villager would take them back. Nothing should disappear.

You're right Morgwenna this is slowing down multiple trading significantly!  not to mention the crashes to desktop possibly corrupting game saves and losing your data.

Should add I'm also on version 1.4.2.0 but playing Bedrock Edition on Windows 10. 
First noticed this only yesterday and not sure when it started.  Mainly noticed it just with farmers as I was trading multiple stacks of farm items.  Today I tried it in another world and with other villager trades and items (both worlds I tried are old worlds from previous versions btw.).
I've had the game crash a few times if you click to trade again very fast after just having done one.  It crashes to desktop.

I came on to report a similar bug but add to yours as ours seem symptoms of the same problem.

Used to be able to place say a stack of iron to trade and click to trade and just keep trading over and over until you don't have enough remaining to stack to trade. 

Now, intermittent crashes of the game if I try to quickly retrade before putting bought item in my inventory.  (I think it used to automatically go into your inventory but now it just floats around?)

EDIT: now remember bought items did float but also could accumulate and you could keep trading further items.  Added more info and video link to the related bug report: https://bugs.mojang.com/browse/MCPE-32635 (Thanks for creating that bug report Morgwenna)

Also sometimes it doesn't count the items you've leftover to trade, as per picture uploaded.  (In the picture, just traded some iron and the emerald I bought is just floating there and it's not counting the remaining iron to trade)
So remaining items to trade need to be moved out of trading square and in again before counted to trade, e.g. move the stack of iron out and in again before it offers an emerald to trade.

Q@moonshine77
I tried your trick of making the top cover of the mob farm slabs. At the same time I increased the spawning height inside taller from 2 blocks up to 3 as is in this video https://www.youtube.com/watch?v=lcgafxZ7iJo&feature=youtu.be

I put slabs ontop 'right side up' (so that they are taking up the bottom half of the block and have air above them and you can't put torches ontop of them. (In Java upside down slabs (and stairs) can spawn things but I hope not in Bedrock Edition? - it's not differentiated anywhere, they just say "slabs".

My results - after hours of testing it made my spawn rates in mob farm go down to by a factor of 5 or more. Can't be sure if raising the height inside affected as I may have got endermen taking up those rare spawn chances more too. Who knows if I had mobs spawned elsewhere that took up the mob cap. Have been going on killing sprees around and making sure everything is lit up to make the mob spawner the only place to spawn.

I should make it two high and retest. Dangerous, have now seen my mob farm from the mob's perspective, fell into the chute while changing the roof over. lol

Perhaps things have changed in current version v1.2.13 since you last reported?
Haven't tried the open sky approach but will do. Wonder what is working for people at the moment?

I mentioned the same bug report you did as it hasn't been marked as a duplicate yet which seems strange.

Brian Green
__deCoroftheMatter, please read the comments before commenting! There is a known issue. There are extremely painful workarounds that must be done until it gets fixed.

Watch the video posted by Gruva: https://www.youtube.com/watch?v=5y2Jnwi3hKE

It explains how the spawn mechanics are working now. (This is not the intended Minecraft behavior, hence why this bug is still "Open")__

Thanks for responding. I hadn't read ALL of the comments, true, now have. Was only trying to help by sharing a workaround that worked on my survival world with a mob farm similar to the OP. My main gist was don't have an animal farm near your mob farm, or turn your simulation area down to not encompass your animal farm like I did. Agree, before I turned my simulation distance around, when near my hundreds of animal farm, there weren't enough mobs spawning to complete the game in good time and my mob farm was barely working at all. It's back now.

Thanks for the link to Gruva's video on "Testing Mob Spawning in Minecraft Bedrock Engine (BTU, Win10, PE) Minecraft 1.2.10". He does some great simulations! I saw his results where mobs were not spawning below y level 30. It is not how spawn mechanics are working now. This bug of not spawning below level 30, among other spawning bugs (e.g. mobs can't spawn on transparent blocks anymore, carpets and slabs) were fixed in v1.2.13 released April 3, 2018.

Did you see his video done the next day after the video above, after a new section on bedrock edition mob spawning was added to the wiki page, https://minecraft.gamepedia.com/Spawn#Bedrock_Edition. His video "Tutorial - How it Works, Mob Spawning, Minecraft Bedrock 1.2.10 (Win10 & PE)" https://www.youtube.com/watch?v=srAL6EpwucQ&t=307s summarises the Bedrock Edition mob spawning in the comments and shows some of how it works.

The wiki "spawn" page, I have some queries on. It is great to confirm there is a global mob cap and that explains why on my world, reducing my simulation distance back down to 4 made spawns happen in my mob farm again, as I stand at the base of the 24 block drop, 4 chunks out from where my animal farms begin. Those animal farms, when counted in my ticking area (simulation distance) must have blown out the mob cap that I now know exist, thanks to the wiki..

The mob cap counts all the mobs within your ticking area (set by your simulation distance). It's strange how your ticking area can be larger than the area eligible to spawn around you (32 blocks out from you and up to 6 chunks out only at max). To increase the chance of mobs being spawned closer to you, makes sense to turn that simulation distance down. (Am I right in assuming simulation distance is the radius of chunks coming out from the player? Or is it the diameter of the ticking area circled around the player? (There isn't a wiki page for simulation distance, only one for ticking area))

The spawning wiki says that the mob density cap limits the number of mobs of each type that can spawn within a 9x9 square region of the selected spawning chunk. That's good news for the Aquatic update coming forward since water mobs have a different mob cap. Gruva interpreted the wiki that the mob density cap includes a 9x9 chunk area around the chunk being checked for spawning, but the wiki never says 'chunk area' It says,_ "The mob density cap limits how many mobs of each type and category can spawn within a 9x9 square region surrounding each chunk eligible for spawning"_ Isn't that clear as mud? I hope someone can clarify and update the wiki, if that is a 9x9 chunk area it checks or just 9 more blocks?

Before commenting here I'd seen that spawn wiki page and had mistakenly thought only a few paragraphs were about Bedrock Edition and the rest were about Java. Perhaps there should be two pages as they are so different. It's confusing when so much information is about the java edition all over the internet. The same often doesn't apply to Bedrock Edition. (Doesn't help that they changed the name when trying to find anything but that's another story!).

Can't wait until someone designs a mob spawner, like Gruva recommends to take advantage of how surface spawns are done first then the algorithm goes vertically down and tried cave spawns beneath that successful spawn block. A two level mob spawner with surface and cave areas to spawn should do better in Bedrock Edition. Then you can fill the surface and cave mob caps more fully.

After writing above comment, found more interesting info on the wiki about mob spawning. https://minecraft.gamepedia.com/Spawn
It is great to know more now about how mobs are spawned in Bedrock Edition. There are mob caps that confirm my findings about having your farm away from where you want mobs to spawn.

The wiki confirms that there is a mob cap, "The global mob cap for natural spawns is set at 200 regardless of difficulty." That makes you think that difficulty won't matter, but apparently it does. Later, under 'pack spawning' says: "Picks a random number of mobs to spawn in the pack. Each mob can have its own min and max pack size, and the pack size can depend on difficulty". It doesn't go into detail about the pack sizes for each mob though.
It does explain the mob density caps as well that are checked and reduce the probability of hostiles being spawned. It is different, and there will be less mobs than on to Java probably to reduce load on tablet and phones unfortunately. 😞