mojira.dev
MC-241172

Rare Datafixer error occured in old world

Resolved
Fixed
8

The bug
I was loading my old worlds in this Pre-release and the world lagged a bit on saving and then I checked logs and saw a problem saving chunk with a Data fixer error.

[17:29:13] [Server thread/ERROR]: Failed to save chunk 9,-18
java.lang.NullPointerException: Cannot read field "d" because "$$0" is null
	at ddm.b(SourceFile:23) ~[1.18-pre1.jar:?]
	at com.mojang.serialization.codecs.RecordCodecBuilder$Instance.lambda$ap2$4(RecordCodecBuilder.java:215) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.codecs.RecordCodecBuilder$2.encode(RecordCodecBuilder.java:112) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.MapCodec$MapCodecCodec.encode(MapCodec.java:96) ~[datafixerupper-4.0.26.jar:?]
	at xz.a(SourceFile:34) ~[1.18-pre1.jar:?]
	at xv.a(SourceFile:42) ~[1.18-pre1.jar:?]
	at xv.encode(SourceFile:13) ~[1.18-pre1.jar:?]
	at com.mojang.serialization.Encoder.encodeStart(Encoder.java:14) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.codecs.FieldEncoder.encode(FieldEncoder.java:24) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.MapCodec$1.encode(MapCodec.java:39) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.codecs.RecordCodecBuilder$Instance$4.encode(RecordCodecBuilder.java:222) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.codecs.RecordCodecBuilder$2.encode(RecordCodecBuilder.java:112) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.codecs.KeyDispatchCodec.encode(KeyDispatchCodec.java:92) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.MapCodec$MapCodecCodec.encode(MapCodec.java:96) ~[datafixerupper-4.0.26.jar:?]
	at com.mojang.serialization.Encoder.encodeStart(Encoder.java:14) ~[datafixerupper-4.0.26.jar:?]
	at dem.a(SourceFile:72) ~[1.18-pre1.jar:?]
	at det.a(SourceFile:119) ~[1.18-pre1.jar:?]
	at dfb.a(SourceFile:53) ~[1.18-pre1.jar:?]
	at dev.a(SourceFile:81) ~[1.18-pre1.jar:?]
	at cqn.a(SourceFile:421) ~[1.18-pre1.jar:?]
	at cqn.a(SourceFile:373) ~[1.18-pre1.jar:?]
	at acp.a(SourceFile:758) ~[1.18-pre1.jar:?]
	at acp.e(SourceFile:457) ~[1.18-pre1.jar:?]
	at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[?:?]
	at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179) ~[?:?]
	at it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap$ValueIterator.acceptOnIndex(Long2ObjectLinkedOpenHashMap.java:1736) ~[fastutil-8.5.6.jar:?]
	at it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap$ValueIterator.acceptOnIndex(Long2ObjectLinkedOpenHashMap.java:1723) ~[fastutil-8.5.6.jar:?]
	at it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap$MapIterator.forEachRemaining(Long2ObjectLinkedOpenHashMap.java:1260) ~[fastutil-8.5.6.jar:?]
	at it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap$ValueIterator.forEachRemaining(Long2ObjectLinkedOpenHashMap.java:1723) ~[fastutil-8.5.6.jar:?]
	at it.unimi.dsi.fastutil.objects.ObjectSpliterators$SpliteratorFromIterator.forEachRemaining(ObjectSpliterators.java:1194) ~[fastutil-8.5.6.jar:?]
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484) ~[?:?]
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[?:?]
	at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[?:?]
	at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[?:?]
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:?]
	at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[?:?]
	at acp.a(SourceFile:454) ~[1.18-pre1.jar:?]
	at ada.a(SourceFile:305) ~[1.18-pre1.jar:?]
	at adc.a(SourceFile:741) ~[1.18-pre1.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:561) ~[1.18-pre1.jar:?]
	at net.minecraft.server.MinecraftServer.b(SourceFile:585) ~[1.18-pre1.jar:?]
	at fcg.a(SourceFile:87) ~[1.18-pre1.jar:?]
	at net.minecraft.server.MinecraftServer.w(SourceFile:684) ~[1.18-pre1.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:270) ~[1.18-pre1.jar:?]
	at java.lang.Thread.run(Thread.java:831) [?:?]

Comments 11

Does MC-239610 describe your issue?

This seems different due to it being a NullPointerException

Can confirm having the same types of errors.

[00:41:39] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 3653ms or 73 ticks behind
[00:44:31] [Server thread/ERROR]: Failed to save chunk 10,-21
java.lang.NullPointerException: Cannot read field "d" because "$$0" is null
        at ddm.b(SourceFile:23) ~[server-1.18%20Pre-release%201.jar:?]
        at com.mojang.serialization.codecs.RecordCodecBuilder$Instance.lambda$ap2$4(RecordCodecBuilder.java:215) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.RecordCodecBuilder$2.encode(RecordCodecBuilder.java:112) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.MapCodec$MapCodecCodec.encode(MapCodec.java:96) ~[datafixerupper-4.0.26.jar:?]
        at xz.a(SourceFile:34) ~[server-1.18%20Pre-release%201.jar:?]
        at xv.a(SourceFile:42) ~[server-1.18%20Pre-release%201.jar:?]
        at xv.encode(SourceFile:13) ~[server-1.18%20Pre-release%201.jar:?]
        at com.mojang.serialization.Encoder.encodeStart(Encoder.java:14) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.FieldEncoder.encode(FieldEncoder.java:24) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.MapCodec$1.encode(MapCodec.java:39) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.RecordCodecBuilder$Instance$4.encode(RecordCodecBuilder.java:222) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.RecordCodecBuilder$2.encode(RecordCodecBuilder.java:112) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.KeyDispatchCodec.encode(KeyDispatchCodec.java:92) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.MapCodec$MapCodecCodec.encode(MapCodec.java:96) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.Encoder.encodeStart(Encoder.java:14) ~[datafixerupper-4.0.26.jar:?]
        at dem.a(SourceFile:72) ~[server-1.18%20Pre-release%201.jar:?]
        at det.a(SourceFile:119) ~[server-1.18%20Pre-release%201.jar:?]
        at dfb.a(SourceFile:53) ~[server-1.18%20Pre-release%201.jar:?]
        at dev.a(SourceFile:81) ~[server-1.18%20Pre-release%201.jar:?]
        at cqn.a(SourceFile:421) ~[server-1.18%20Pre-release%201.jar:?]
        at cqn.a(SourceFile:373) ~[server-1.18%20Pre-release%201.jar:?]
        at acp.a(SourceFile:758) ~[server-1.18%20Pre-release%201.jar:?]
        at acp.e(SourceFile:457) ~[server-1.18%20Pre-release%201.jar:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[?:?]
        at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179) ~[?:?]
        at it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap$ValueIterator.acceptOnIndex(Long2ObjectLinkedOpenHashMap.java:1736) ~[fastutil-8.5.6.jar:?]
        at it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap$ValueIterator.acceptOnIndex(Long2ObjectLinkedOpenHashMap.java:1723) ~[fastutil-8.5.6.jar:?]
        at it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap$MapIterator.forEachRemaining(Long2ObjectLinkedOpenHashMap.java:1260) ~[fastutil-8.5.6.jar:?]
        at it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap$ValueIterator.forEachRemaining(Long2ObjectLinkedOpenHashMap.java:1723) ~[fastutil-8.5.6.jar:?]
        at it.unimi.dsi.fastutil.objects.ObjectSpliterators$SpliteratorFromIterator.forEachRemaining(ObjectSpliterators.java:1194) ~[fastutil-8.5.6.jar:?]
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484) ~[?:?]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[?:?]
        at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:?]
        at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[?:?]
        at acp.a(SourceFile:454) ~[server-1.18%20Pre-release%201.jar:?]
        at ada.a(SourceFile:305) ~[server-1.18%20Pre-release%201.jar:?]
        at adc.a(SourceFile:741) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.a(SourceFile:561) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.b(SourceFile:585) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.a(SourceFile:845) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.w(SourceFile:684) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.a(SourceFile:270) ~[server-1.18%20Pre-release%201.jar:?]
        at java.lang.Thread.run(Thread.java:831) [?:?]
[00:44:32] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 2175ms or 43 ticks behind

Same message here:

 

 

[09:59:54] [Server thread/ERROR]: Failed to save chunk 70,1006
java.lang.NullPointerException: Cannot read field "d" because "$$0" is null
        at ddm.b(SourceFile:23) ~[server-1.18%20Pre-release%201.jar:?]
        at com.mojang.serialization.codecs.RecordCodecBuilder$Instance.lambda$ap2$4(RecordCodecBuilder.java:215) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.RecordCodecBuilder$2.encode(RecordCodecBuilder.java:112) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.MapCodec$MapCodecCodec.encode(MapCodec.java:96) ~[datafixerupper-4.0.26.jar:?]
        at xz.a(SourceFile:34) ~[server-1.18%20Pre-release%201.jar:?]
        at xv.a(SourceFile:42) ~[server-1.18%20Pre-release%201.jar:?]
        at xv.encode(SourceFile:13) ~[server-1.18%20Pre-release%201.jar:?]
        at com.mojang.serialization.Encoder.encodeStart(Encoder.java:14) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.FieldEncoder.encode(FieldEncoder.java:24) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.MapCodec$1.encode(MapCodec.java:39) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.RecordCodecBuilder$Instance$4.encode(RecordCodecBuilder.java:222) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.RecordCodecBuilder$2.encode(RecordCodecBuilder.java:112) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.codecs.KeyDispatchCodec.encode(KeyDispatchCodec.java:92) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.MapCodec$MapCodecCodec.encode(MapCodec.java:96) ~[datafixerupper-4.0.26.jar:?]
        at com.mojang.serialization.Encoder.encodeStart(Encoder.java:14) ~[datafixerupper-4.0.26.jar:?]
        at dem.a(SourceFile:72) ~[server-1.18%20Pre-release%201.jar:?]
        at det.a(SourceFile:119) ~[server-1.18%20Pre-release%201.jar:?]
        at dfb.a(SourceFile:53) ~[server-1.18%20Pre-release%201.jar:?]
        at dev.a(SourceFile:81) ~[server-1.18%20Pre-release%201.jar:?]
        at cqn.a(SourceFile:421) ~[server-1.18%20Pre-release%201.jar:?]
        at cqn.a(SourceFile:373) ~[server-1.18%20Pre-release%201.jar:?]
        at acp.a(SourceFile:758) ~[server-1.18%20Pre-release%201.jar:?]
        at acp.a(SourceFile:516) ~[server-1.18%20Pre-release%201.jar:?]
        at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:714) ~[?:?]
        at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:478) ~[?:?]
        at acp.b(SourceFile:497) ~[server-1.18%20Pre-release%201.jar:?]
        at acp.a(SourceFile:470) ~[server-1.18%20Pre-release%201.jar:?]
        at ada.a(SourceFile:323) ~[server-1.18%20Pre-release%201.jar:?]
        at adc.a(SourceFile:300) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.b(SourceFile:876) ~[server-1.18%20Pre-release%201.jar:?]
        at acd.b(SourceFile:326) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.a(SourceFile:820) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.w(SourceFile:684) ~[server-1.18%20Pre-release%201.jar:?]
        at net.minecraft.server.MinecraftServer.a(SourceFile:270) ~[server-1.18%20Pre-release%201.jar:?]
        at java.lang.Thread.run(Thread.java:831) [?:?]

 

Would anyone mind uploading a copy of a world that produces this error when upgraded?

1 more comments

Please attach a world if possible! Thanks.

This is the same issue as MC-241204 (same stack trace, same result)

Is this still an issue in 1.18 Pre-release 2?

Yes, seen it occur on my other old world

I'll check again to confirm it's still reproducable

Can no longer reproduce, I explored my very large world and seems to be no errors related to this bug.

Welcome 234

Fry

Community Consensus

Important

Datafixer

1.18 Pre-release 1, 1.18 Pre-release 2

1.18 Pre-release 4

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