mojira.dev
MC-312142

The game crashes when playing old Superflat worlds

  1. The game crashes while playing superflat worlds created before the world height expansion in version 1.17.
    Crash report description:
    Exception on worker thread
    java.lang.ArrayIndexOutOfBoundsException: Index -1 out of bounds for length 24

  2. Similarly, the game crashes while attempting to load or generate custom superflat presets that replicates pre-1.17 superflat worlds by including 64*minecraft:air on the bottom layer, though the crash report states this is a different issue

    Crash report description:
    Exception generating new chunk
    java.lang.NullPointerException: Cannot invoke "net.minecraft.world.level.block.state.BlockState.isAir()" because "block" is null

Neither of these crashes occur when running version 26.3

Attached are crash reports for both issues

Attachments

Comments 5

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I also get this crash in 26.4-snapshot-1.

Crash log: java.lang.ArrayIndexOutOfBoundsException: Index -1 out of bounds for length 24 at NoiseBiomeChunk.getSection(NoiseBiomeChunk.java:62)

My trigger condition: When standing at Y≈-48, game crashes during auto-saving chunks, with experimental datapacks redstone_experiments and minecart_improvements enabled. Vanilla, no mods. Attached my full crash report.

Attached my full crash report.

We hit the same Index 24 out of bounds for length 24 error at NoiseBiomeChunk.getSection:62 → SerializableChunkData.write:451 on an unmodified 26.4 Snapshot 1 dedicated server running Linux aarch64 and OpenJDK 25.0.4.1.

A player connected about 62 seconds before the worker exception; a watchdog report followed one minute later.

Restarting the unchanged jar brought the server back up. Two custom data packs were active and marked incompatible, but their installed files contain no world-generation resources.

We have not identified a repeatable player action or the affected chunk.

These are actually 2 seperate bugs, I didnt realize that when I initially wrote this report.

The first bug mentioned here is MC-312064 and was fixed in 26.4 Snapshot 2,

The second bug is MC-312213 and is still present in 26.4 Snapshot 2

Sorry for any confusion

TheCrimsonReign

Thomas Mojang

Community Consensus

Platform EC

Very Important

Crash

26.4 Snapshot 1

Retrieved