I updated a world from 20w20b to 20w21a. When I logged into the server, this appeared in the console:
[09:44:16] [Server thread/ERROR]: No 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}]
[09:44:16] [Server thread/ERROR]: Exception loading structure piece with id minecraft:rupo
java.lang.RuntimeException: No 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}]
at com.mojang.serialization.DataResult.lambda$getOrThrow$4(DataResult.java:100) ~[vanilla.jar:?]
at com.mojang.datafixers.util.Either$Right.map(Either.java:99) ~[vanilla.jar:?]
at com.mojang.serialization.DataResult.getOrThrow(DataResult.java:93) ~[vanilla.jar:?]
at css.<init>(SourceFile:114) ~[vanilla.jar:?]
at clk.a(SourceFile:137) ~[vanilla.jar:?]
at cgv.a(SourceFile:424) ~[vanilla.jar:?]
at cgv.a(SourceFile:175) ~[vanilla.jar:?]
at yi.l(SourceFile:525) ~[vanilla.jar:?]
at java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source) [?:1.8.0_251]
at alz.c(SourceFile:144) [vanilla.jar:?]
at yu$a.c(SourceFile:541) [vanilla.jar:?]
at alz.w(SourceFile:118) [vanilla.jar:?]
at yu$a.w(SourceFile:550) [vanilla.jar:?]
at yu.d(SourceFile:280) [vanilla.jar:?]
at net.minecraft.server.MinecraftServer.bd(SourceFile:770) [vanilla.jar:?]
at net.minecraft.server.MinecraftServer.w(SourceFile:758) [vanilla.jar:?]
at alz.c(SourceFile:127) [vanilla.jar:?]
at net.minecraft.server.MinecraftServer.v(SourceFile:743) [vanilla.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:695) [vanilla.jar:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_251]
Linked issues
is duplicated by
Attachments
Comments

It doesn't crash the server. It still runs and just shows the error message in the console.
Attached is a snippet from my console that shows it also spamming using No key position_predicate which is in addition to the topic of this issue.

Those tags resemble the generator tags for Ruined Portals.
20w22a
Still a thing.
Still occurring in pre-release 2

This is a snapshot-only problem.
happens for me in 1.16 release... upgraded from 1.15.2 (reset nether).... attached one of the many spams
[media]
Happens for me in 1.16 release (from 1.15) after performing nether reset
[media]
That is a different error Jake.

You are using mods Ahmad.
Hello I'm also experiencing the same problem.
[media]
Are we to understand that since this has been marked as Wontfix that we'll have to essentially ignore that this still occurs ?

The issue you all are referring to is MC-191388, not this.
Oh Okay Thanks!
The spam im seeing on console is exactly like this posted on this issue as seen in consolespam.txt file i attached

@Warren: Was the world opened with any 1.16 development version?
Yes, All of them. I reset the nether for 1.16 so as it was fresh.

https://bugs.mojang.com/browse/MC-184656?focusedCommentId=725578&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-725578
Yes i had seen the post by slicedlime saying a snapshot only issue, however the statement is a tad vague in its meaning. But i gather from your reply its an issue with worlds that have used snapshot and therefor nothing will or can be done about it and a world reset is the only way to get rid of it?
still happening on 1.16.1 and it causes the server to restart and kick everyone
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 happens in 1.16.1 in a world with a newly generated nether dimension. i don't think this is fixed.
[13:39:45] [Server thread/ERROR]: No key replace_with_blackstone in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key vines in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key overgrown in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key air_pocket in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key mossiness in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key cold in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]
[13:39:45] [Server thread/ERROR]: Exception loading structure piece with id minecraft:rupo
java.lang.RuntimeException: No key replace_with_blackstone in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key vines in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key overgrown in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key air_pocket in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key mossiness in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]; No key cold in MapLike[{AirPocket:0b,Overgrown:0b,Mossiness:0.5f,Cold:0b,Vines:1b,ReplaceWithBlackstone:0b}]
at com.mojang.serialization.DataResult.lambda$getOrThrow$4(DataResult.java:100) ~[minecraft_server.jar:?]
at com.mojang.datafixers.util.Either$Right.map(Either.java:99) ~[minecraft_server.jar:?]
at com.mojang.serialization.DataResult.getOrThrow(DataResult.java:93) ~[minecraft_server.jar:?]
at ctt.<init>(SourceFile:115) ~[minecraft_server.jar:?]
at cml.a(SourceFile:137) ~[minecraft_server.jar:?]
at chv.a(SourceFile:431) ~[minecraft_server.jar:?]
at chv.a(SourceFile:176) ~[minecraft_server.jar:?]
at yp.l(SourceFile:524) ~[minecraft_server.jar:?]
at java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source) ~[?:1.8.0_191]
at amn.c(SourceFile:144) ~[minecraft_server.jar:?]
at zb$a.c(SourceFile:545) ~[minecraft_server.jar:?]
at amn.x(SourceFile:118) ~[minecraft_server.jar:?]
at zb$a.x(SourceFile:554) ~[minecraft_server.jar:?]
at zb.d(SourceFile:280) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.aZ(SourceFile:751) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.x(SourceFile:739) ~[minecraft_server.jar:?]
at amn.c(SourceFile:127) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.w(SourceFile:724) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.v(SourceFile:676) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.a(SourceFile:256) ~[minecraft_server.jar:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_191]
Does this crash the server, or does it still run and just shows this in the console?