hearth/docs/minecraft-incidents.md

Minecraft incident log

This file records only observed evidence, actions, and verification results. An entity appearing in a stack trace is a trigger-path observation, not a proven root cause.

2026-09-19 — WorldOfSosal crashes in Sable block-change handling

Impact

• minecraft-server-wowMineMap.service terminates while a player is online.
• Public Minecraft endpoint is store.hectic-lab.com:25568.
• Server is intentionally stopped after the latest crash to prevent repeated crash-save cycles while recovery is investigated.

Observed evidence

All crash reports contain sable@2.0.5 in LevelAccelerator.getBlockState, followed by ArrayIndexOutOfBoundsException where the requested section index exceeds the world section array length of 24.

UTC timestamp	Crash report	Observed trigger path	Exception
18:47:03	crash-2026-09-19_18.47.03-server.txt	EnderMan$EndermanTakeBlockGoal.tick	index 38 / length 24
18:52:17	crash-2026-09-19_18.52.17-server.txt	GlowSquid.aiStep → RedStoneOreBlock.stepOn	index 33 / length 24
19:14:46	crash-2026-09-19_19.14.46-server.txt	Skeleton.tick → RedStoneOreBlock.stepOn	index 34 / length 24

Evidence locations on neuro:

/srv/minecraft/wowMineMap/crash-reports/
/srv/minecraft/wowMineMap/logs/latest.log

Actions performed

UTC timestamp	Action	Result
17:51	Archived current world before recovery	Archive checksum recorded
18:08	Set randomTickSpeed=0	Server started, but later crashed from an entity block change
18:48	Set mobGriefing=false	Prevented Enderman block pickup only; later crashes still occurred
18:54	Archived post-crash world	Archive checksum recorded
19:00	Moved Boss offline player NBT from (3299.067, 142.630, 8613.742) to (3296, 500, 8608) in crafting_azeroth:azeroth	Only Pos and Dimension changed; later crash still occurred
after 19:14 crash	Stopped minecraft-server-wowMineMap.service	Prevented further automatic crash/restart saves

Recovery artifacts

/srv/minecraft/backups/wowMineMap-before-sable-recovery-20260919T175139Z.tar.zst
/srv/minecraft/backups/wowMineMap-after-sable-crashes-20260919T185445Z.tar.zst
/srv/minecraft/wowMineMap/world/playerdata/1c189af5-2713-3fa6-bcc4-893dfadedfa4.dat.before-relocation

Conclusions supported by evidence

• Public proxy and reverse tunnel are not the failure point: server-list ping succeeded before later in-world crashes.
• The failure is not limited to Endermen, random ticks, or one player position.
• Sable's block-change callback is present in every captured crash.

Not established

• Exact corrupt chunk, block, or mod data.
• Whether world data is corrupt, Sable itself is defective, or another mod is supplying incompatible world state.
• Whether deleting any chunk, region, or Sable state would be safe.

External research

No exact upstream match was found for Sable 2.0.5 on NeoForge 1.21.1 with LevelAccelerator.getBlockState and a requested section index of 33, 34, or 38 against a section array of length 24.

Related but non-identical upstream reports:

• Sable #776 documents an ArrayIndexOutOfBoundsException associated with unusual dimension height bounds. This is relevant to section-coordinate handling, but is an older version and different stack trace.
• Sable #1087 documents a LevelAccelerator.getBlockState recursion during block-shape processing. The failure type differs.
• Sable #820 documents a ticking-entity block-change crash. The reported downgrade to 1.1.3 helped that distinct recursive-update failure; it is not evidence for this crash.
• Sable #1223 documents a different ArrayIndexOutOfBoundsException in voxel-neighborhood handling. Its suggested Lithium setting only reduced crashes for some reporters and is not a verified mitigation here.

Sable 2.0.4 and 2.0.5 release notes mention other block or contraption crash fixes, but not this exception. No version upgrade or downgrade is currently evidence-backed as a production fix.

Next recovery step

Use a disposable full-world copy to test a supported Sable/physics integration mitigation. Do not restart production, delete region files, or overwrite a backup until that test gives reproducible evidence.