"No key position_predicate in MapLike" console spam

I too am seeing this on my Vanilla world.  The world was generated in 1.14 and upgraded through the 1.15.x's to 1.16 and then 1.16.1  My console dumped this log a few times now.  Each time, the server kept running and a player was able to continue playing.

I have just updated my 1.15.2 server to 1.16.1 and am having the same issue. I was watching the terminal output and noticed that as stated previously the server beings to throw errors every time a player nears a village or crop farm. Thankfully I have many backups. I'm curious, would using the "Optimize World" feature of Java Minecraft be a way to stop this problem? I am going to test it out and will report my findings here.

EDIT: Errors still occur even after using the "Optimize World" feature with "Erase Cached Data" enabled. See "Error.txt" for output and seed information.

Adding this comment as I commented on MC-184656 not realziing it was a different error....
The logs spam is incredibly massive, this is a 1.15.x world which was upgraded to 1.16 directly.

Here is just one instance of them, they sometimes go off several in a row with no errors above or below them.

Edit: Posting the comment to have it posted to the correct issue.
Edit: I'm going to keep an eye out now I'm on 1.16.1 as others have said it still occurs, its not in my latest.log as of right now.
Edit July 18 2020: Its doing it again, its still a problem, not just an initial update spam

Hi, I would also like to throw out that this error also appears in Spigot servers. 

Hashtag me too. Updated from 1.15.2 to 1.16.1.

Is there anyway to fix this issue? I suppose we can open the world in a program like MCEdit and regenerate those chunks, (maybe that will help). Seems that at first join Server TPS drops very low, maybe around 5-6 TPS. After the second join onto the server, TPS goes back up to 20.0, however console spam and errors are still there. Seems to be a major issue that should be prioritized.

Me too. Updated from 1.15.2 to 1.16.1 - running Spigot.

https://pastebin.com/hniijMR0

Also - I had the same issue as Brandon Li describes with server TPS. I ended up moving to a more powerful server machine to solve the issue - but the 1.16 optimisation for chunk generation seems very poor.

I'm particularily surprised of the performance difference especially between 1.15.2 to 1.16.1. It seems before my server computer wouldn't lag, and it would stay at a solid 20/20 TPS. After the upgrade, it seems that everything lags. TPS drops to be around 10, (and can even reach 5). Loading new chunks take a good amount of seconds before they render. Also, saving the world for me gives me another error saying "my computer was not strong enough to handle saving the world" which a couple seconds after, the console said I saved the world. The computer also freezes a ton, which was not something I commonly saw before.

Confirming logger spam and infernal lag at times. See attached 

World was generated locally in version 1.14., moved to Realms 1.14.4, then moved to CubedHost in 1.15.2, and today with DIM-1 deleted it was updated directly to 1.16.1. The world was never run on any snapshot version.

The spam always triggers on server start, almost every time a player joins, sometimes on player death, and at random times.

On every occasion it caused the server 40-80 (rarely 130) ticks delay!

Can confirm all issues above, consistent spam when users join. Handle certain actions, death...., Worlds generated 1.14, moved to 1.15.2, moved to 1.16.1.... This is in all worlds, Nether was wiped and reset for 1.16.1 and seeing issues there as well.

I can also confirm the console spam and missing blocks in the following use case.

World built on 1.15.2 then loaded on 1.16.1 server. Teleport to a chunk where village was never or partially loaded and blocks will be missing.
Console spam occurs: .

Server is running paper but the issue is evidently present in the vanilla jar.

@qbdown i heard in paper if you set these settings:

async-chunks:
enable: false
threads: -1

the problem will go away. However, this is only a temporary solution, because you should switch async-chunks to true after due to it optimizing chunks better.

The above comment is false, please don't disable that config it doesn't relate to this issue

It wasn't my original comment... Somebody said it here in this github: https://github.com/PaperMC/Paper/issues/3654

It did fix some people's issues though, so I don't think it doesn't work.

New snapshot and still no fix

I wanna play 1.16 from my 1.15 world but I cant because of this silly bug ruined my world. replace some village block with air ...

Please fix this instead of adding new features...

Also having this issue, it's amounting a lot of lag on our server, waiting for a fix. New features aren't as important as performance, please understand our frustration. We haven't had performance like 1.12.2 in a long time. It's making multiplayer harder and harder to play on.

Issue present on our 1.14.4 world when attempting to update to 1.16.1(vanilla, spigot, and paper) 

Converted over 125 worlds so far, and almost every 6th world has this come up. It's a consistent issue.

Are there any admins or mods which can help us find a work around for this issue or will let us know that they are working on this? Thank you.

happening in 1.16.1 and it's causing the server to restart and kick everyone anytime this happens:

1:32:54 PM  CONSOLE:  key replace_with_blackstone in MapLike[{AirPocket:1b,Overgrown:0b,Mossiness:0.2f,Cold:0b,Vines:0b,ReplaceWithBlackstone:0b}]; No key vines in MapLike[{AirPocket:1b,Overgrown:0b,Mossiness:0.2f,Cold:0b,Vines:0b,ReplaceWithBlackstone:0b}]; No key overgrown in MapLike[{AirPocket:1b,Overgrown:0b,Mossiness:0.2f,Cold:0b,Vines:0b,ReplaceWithBlackstone:0b}]; No key air_pocket in MapLike[{AirPocket:1b,Overgrown:0b,Mossiness:0.2f,Cold:0b,Vines:0b,ReplaceWithBlackstone:0b}]; No key mossiness in MapLike[{AirPocket:1b,Overgrown:0b,Mossiness:0.2f,Cold:0b,Vines:0b,ReplaceWithBlackstone:0b}]; No key cold in MapLike[{AirPocket:1b,Overgrown:0b,Mossiness:0.2f,Cold:0b,Vines:0b,ReplaceWithBlackstone:0b}]

This is such a big bug and it's annoying that Mojang hasn't even assigned anyone to it yet 😡 PaperMC has had 68 builds already since 1.16, c'mon Mojang! 

Agreed With Raymond Woof !!!

Needs to be fixed...

Same happens to me after upgrading vom 1.15:

[19:30:20] [Server thread/ERROR]: No key position_predicate in MapLike[{location_predicate:
{predicate_type:"minecraft:block_match",block:"minecraft:water"}
,output_state:{Properties:
{level:"0"}
,Name:"minecraft:water"},input_predicate:{predicate_type:"minecraft:block_match",block:"minecraft:dirt"}}]; No key position_predicate in MapLike[{location_predicate:
{predicate_type:"minecraft:block_match",block:"minecraft:water"}
,output_state:{Properties:
{level:"0"}
,Name:"minecraft:water"},input_predicate:{predicate_type:"minecraft:block_match",block:"minecraft:grass_block"}}]; No key position_predicate in MapLike[{location_predicate:
{predicate_type:"minecraft:always_true"}
,output_state:{Properties:
{snowy:"false"}
,Name:"minecraft:grass_block"},input_predicate:{predicate_type:"minecraft:random_block_match",probability:0.1f,block:"minecraft:grass_path"}}]; No key position_predicate in MapLike[{location_predicate:
{predicate_type:"minecraft:block_match",block:"minecraft:water"}
,output_state:{Name:"minecraft:oak_planks"},input_predicate:{predicate_type:"minecraft:block_match",block:"minecraft:grass_path"}}]

I am also having this issue. Here are the details:

1. we just, in the last hour, upgraded from spigot 1.15.2 to paper 1.16.1

2. we have never, ever, used any snapshots - either 1.15.x snapshots or 1.16 snapshots of any server version

3. we reset world_the_nether and world_the_end but we can NOT reset world

4.  we run multiverse and multiverse portals. All the various worlds created via multiverse and linked via multiverse portals are fine, and the portals are working fine

5. we deleted all of our nether portals before the upgrade and have not recreated them

6. We removed all of our coreprotect regions before updating the plugins.

We are getting all the same no key position_predicate in MapLike that everyone else is reporting, however we haven't had any lag as yet and we haven't had any users kicked off.

I noticed in the comments that one of the devs thinks this is due to a snapshot being run on the world before, but as we have never run a snapshot, that can't be the cause.

I have this same issue. I initially created our world in 1.12.2, though it was just a small survival island spawn that I updated to 1.13.X after setting a few things up (using mods to help with creation that wouldn't have made the jump). It's been vanilla ever since. I updated to 1.14.1 or .2 and had no issues, eventually hitting 1.14.4 that it was on until yesterday.

Yesterday after I changed to 1.16 (running the vanilla Minecraft server jar from the official download site) I've started getting this spam in my console log. It doesn't seem to occur around when people are joining, but only when people are online. I'll monitor and pass along anything I notice.

So lately I've been experimenting with upgrading my server for my users. This bug seems to only occur when chunks that contain villages are loaded that were generated prior to the 1.16.1 upgrade. Since I run a modded server, I have used the WorldEdit beta to delete the chunks those villages are in and a reasonable area around them to account for changes to the generator.

This seems to remove the messages. Your mileage may vary, and you have to consider that doing this may remove content created by your users. How to do this on vanilla would be deleting the chunks in an editor while offline and reloading it.. though there may be other methods.

Still a problem, updated my server from 1.15.2 to 1.16.1 and this issue started to appear, causing some lag whenever the server is started.
Users have reported missing blocks in villages, a developer suggested this could be happening due to the server previously running a snapshot version,
however we have never used snapshots or anything that should affect these blocks in any way. I hope they assign someone on this soon and it gets fixed. 🤞
In the meantime, if you are not willing to wait this out, you can do as James suggested above.

Concur with James. I was able to identify three regions in our default world that had this issue, by looking for villages in our ServerTutorialPlus tours. After verifying that no other player content existed in those areas (they were intentionally outside the usual player areas), I deleted the relevant region and poi files and restarted the server to regenerate them. I then visited them to reestablish the tutorial points. In one of them, the terrain had been altered subtly, but otherwise the process was unproblematic. The errors no longer occur. As noted above, if you have player content in the affected areas, more nuanced decisions may need to be made.

I've been doing extensive testing around that specific problem. First, as James and Richard mentioned, villages that are on the edge of the map or containing chunks that have not been loaded are affected. I attached a few screenshots as examples.

I tested successfully the following three workarounds:

1. Before the upgrade, if you have access to a dynamic map such as dynmap, identify the villages that contain chunks that are not loaded (i.e. on the edge of the map or in areas that are not entirely loaded) and preload them before the upgrade by simply moving a player at the center of the village

2. After the upgrade, fix the corrupted chunks by using the Worldedit following commands:

   # Select your area using the wand or //pos1 and //pos2 commands
   # Regenerate the area
   //regen

3. If your running a pure vanilla server and therefore don't have access to Worldedit, identify the chunk(s) affected by the bug using F3 in game, stop the server, backup the world folder, then delete the affected chunks using MCASelector (https://github.com/Querz/mcaselector/releases).  As an example, here is the command you can use if your server does not have a GUI.

java -Xms1G -Xmx1G -jar mcaselector-1.12.jar --headless --mode delete --world /mnt/minecraft/minecraft-server/world/region/ --query "xPos >= 6 AND xPos <= 15 AND zPos >= -126 AND zPos <= -114"

Regarding my server, it's running Paper and I've never used any snapshot.

The world was created in 1.14.4, then upgraded to 1.15.1, then 1.15.2, then 1.16.1.

EDIT - 2 weeks after I migrated
Even if I preloaded all my villages, I got these errors a few times after the upgrade when my players went into specific areas of the map (I still don't understand which areas triggered that error...). I've not observed any data corruption though, so AFAIK it was just noise in the server's console. It's been more than 2 weeks I migrated my server and it's been a few days without any error in the server's console.

I have a feeling that this bug is not gonna fix in 1.16.2 ...

it is not even assign to someone!

we 1.15.2 player should suffer!

If not, several workarounds have been documented above. It took me about 30 minutes to clear the issue on my servers. YMMV.

Is this just affects the console? or its like Village corruption?
A console log filter could be a workaround?

Village corruption as you can see in the screenshots

Only not fully loaded villages are affected?, or all villages are?
Im trying to update loading all incomplete villages but still throws the error.

Updating the world in single player to 1.16, and then,  using the optimize world option almost nullifies this error, only sends the error one every 15 minutes or even more time between errors.

Edit: It seems that after a restart of the server, the error messages stopped 

@Karim_Rivera, when optimizing the world in single player mode, did you use the "Erase Cached Data" feature? Also that was to 1.16 and not 1.16.1 correct?

@Hudson_Bradley , I did not use the "Erase Cached Data", and it was 1.16.1.
If its useful, i also tried to load all villages in the world before updating, but still i couldn't find all of them,so the error continued, until i optimized the world in single player.
 

In 20w29a.

Massive console spam here, as well, since updating our multiplayer server from 1.15.2 to 1.16.1.  It can be differing blocks, but most commonly wheat, water and grass blocks.  We're on PaperMC, most current build.

Guys does anyone know that this fix in 1.16.2 or not?

Almost 1 Month pass and nothing. no update even is this page. only confirmation comments.

none of fixes above help me fix this error and bug and my village get corrupted!

doesn't it really important to Mojang that 1.15.2 world getting corrupt in 1.16?

It's really disappointing ...

How many time will you take to solve this error? I won't update my server with this spam in the console and my users are asking for an update, we only get notified of strange bot updates from "Open -> Open" (wtf) and we are waiting for a solution since a month ago...

I managed to stop the console spam by adding --forceUpgrade to the end of the bat file. It took a very long time to go through each chunk, and once that was done the server started, initially without errors. Once people were on it, the errors came again (but less of them) but this went away after a restart (without --forceUpgrade), and I haven't seen them since. Hope this is helpful to someone else.

@Suzy Shipman Great this solved the issue. Do you know if there is a way to do this while the server is running. I have 20-50 people on my server at any one time and I dont want to take the server down for a long period of time also I dont have access via my host to change the bat file. 

@Kenneth Campbell sorry I don't know. Mine is just a small server for family and friends that lives on a spare PC in the house.

@Kenneth Campbell Cannot be done while the server is up. By definition the --forceUpgrade flag is a server startup option.

## Force Upgrade (1.13+) / Optimize World
#
# Possible values: true, false
# Default: false
#
# Forcefully upgrade the full world prior to the start of the server.
# This option should be disabled after the first successful run and does not automatically disable itself.
#
## It is HIGHLY recommended that you complete a backup prior to enabling this!
#
force-upgrade=false

as defined by CubedHost's .tweaks file.

I did all these in my server. yes it's reduce the amount of console spam and village corruption BUT try start exploring some villages in your world. (Far one for example) and it will appear again! it is not a way to fix this and it still has some risks. I hope Mojang will at least assign it to someone! 

@@unknown - Thanks for your post it had a lot of valuable information. I ran two tests with my server's world, not highly scientific, but I thought I'd share my results. 
Test A - Resulted in more error spam than Test B

• Used the latest paperMC at the time, ran with --forceUpgrade

• There were no errors during the updrade but as soon as someone logged on the error spam started occurring. Eventually the errors stopped but that might be more to do with us not really doing anything on the server.

Test B - Still had error spam, but less than Test B

• tried to prepare the world using the methods outlined in your post

• Used the latest paperMC at the time, ran with --forceUpgrade

• after logging in we still saw the error spam, but less than before. We have not pushed the borders of the world much since then, so it would be interesting to see if the errors increase in frequency once we start exploring again.

@j b - did you restart the server a second time without --forceUpgrade? I found that initially I got the spam when people logged on, but after doing another restart without --forceUpgrade this seems to have gone.

--forceUpgrade sould always be done when starting your server the first time after upgrading to any major version. For example from 1.15.2 to 1.16.x
This, however, does not solve the issue described here as it also occures when --forceUpgrade has been initially used.

So far, the only thing I could do to, at least, get rid of the console spam is installing a plugin called "Console Spam Fix 1.8.3".
You, however, need a spigot or paper server to do so...

Still no fix for this issue, the console spam isn't constant as my map is more explored but newly discovered villages are floating on air blocks and I get a mess of console spam when they are discovered. 

MC-176034

the bug I mentioned above seems to be more important than village corruption from 1.15.2 to 1.16 ...

It was fixed yesterday!

Mojang Priority is NICE!!

I really wish Mojang would fix this. I can't run my server because it just crashes when I near certain villages.

One important thing for fix, it has to get this bug in vanilla server. If not they ignore the bug, like they have for pillager spawn like crazy and get the no despawn tag (even when you try force get despawn tag thru command block).

So, in this case when it confirm even vanilla has the bug, do not say use paper or spigot (only do more harm in this case, for mojang can say use modded server and not fix it). They are weary hard on this point, even if it mojangs fault. 

But say what server you use, can have inflict at mojang don´t get any on the case (is not to important to mojang to fix, if it more modded servers get this error and not vanilla servers).

So i recommend put in you world in vanilla jar and see if you encounter same error, yes you can do this even if modded servers split the worlds (you can put the world in one world folder, but if only overworld some have are the error you only need that).

I have this error to and has see grass-block instead for some if the leaves in a village (and some places i teleport to I get errors (new gen villagers i guess, it most water and grass errors )).

It was confirmed on 25th of June (over a month ago) to also affect vanilla Minecraft. It's literally the 2nd or 3rd response.

As @James_Elliott said, it has been reported in vanilla minecraft servers. The sixth comment on this bug report was by me for that very thing. Would providing my entire server folder help speed up the patching process?

23/Jun/20 5:01 PM Was when this was created.... WHERE IS OUR FIX MOJANG.

Dakoda it takes time for Mojang to fix problems. So wait they will get to it.

Anthony, this can not be another bug that is open for 5 freaking years like some of their issues. If you ran a server you would understand.

What I don't understand is why Mojang releases new versions with very few changes, making us feel they are incredible, but the performance is getting worse and worse, with a lot of bugs.

When I can update my server to 1.16.2 (with the bug fixed, I hope) 1.17 (with a lot of bugs) will be already released...

I understand the frustration, but I can understand this is not high priority for Mojang to fix this. As I said earlier in my previous comment there are workarounds, even for those running vanilla servers. As many users reported, these errors will stop a few days / weeks (depending on your player's activity) after your server is migrated to 1.16. And it only affects partially created villages. That bug won't affect player's builds.

Same Problem with massive console spam... Please fix.

For those of us who run multiplayer servers, the console spam makes it impossible to see anything else in console and logs must be searched to avoid scrolling through miles of error text.  And Minecraft gods help you if your search term is included in that spam.  This really needs to be fixed soon.

This issue really needs higher priority. Am i safe to assume the fix won't be in 1.16.2 by now?

No. 1.16.2 is still in development. It can still be fixed

in my opinion it's not gonna fix 80% in 1.16.2

Assigned and fixed in 2 days, finally some good news 🙂 

Yes, this is great news.  

Does anyone know if there are specific steps to take in order to properly upgrade the server? The way that I just tried still gave me a bunch of spam and even reset several of my chunks. My base is completely gone.