Roastd / Minecraft

A world-generation bug crashed the server

What it looks like in your log

Exception ticking world
	at net.minecraft.world.level.levelgen.structure.StructureCheck.checkStart

What causes it

The structure-lookup cache was corrupted while checking structures during world generation, usually from many structure lookups happening at once as players explore or use a structure compass.

How to fix it

Pre-generate the world with Chunky (console: "chunky radius 5000" then "chunky start") so this generation happens up front, and ease off structure searches in fresh terrain. It is safe to restart; the world is not damaged.

Errors that travel with this one

• A world-generation feature is writing outside its chunkDetected setBlock in a far chunk [15, 7], pos: BlockPos{x=250, y=64, z=120}, status: minecraft:features
• The server stalled for too long and the watchdog stepped inThe server has not responded for 60 seconds! Creating thread dump
• A region file is cut shortRegion file ./world/region/r.0.0.mca has truncated header: 0
• The server cannot save chunksFailed to save chunk 12, -4
• A chunk has grown enormousSaving oversized chunk [12, -4] (2097152 bytes)
• Chunks are corrupt or in the wrong placeChunk file at [12, -4] is in the wrong location; relocating. (Expected ChunkPos [12, -4], got ChunkPos [11, -4])