Server crash while walking on world

[jorgebonafe]

I just had a crash. Here's the report. Edit. This was on SquidASwimming, not the latest release.

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---- Minecraft Crash Report ----
// Don't be sad, have a hug! <3

Time: 21/02/18 02:55
Description: Exception getting block type in world

java.lang.NullPointerException
at apy.a(SourceFile:178)
at apy.j(SourceFile:158)
at apy.w_(SourceFile:278)
at aab.a(World.java:2430)
at abw.e(Chunk.java:864)
at abw.a(Chunk.java:635)
at aab.f(World.java:432)
at adu.a(WorldGenDungeons.java:115)
at acy.a(ChunkProviderGenerate.java:516)
at iy.a(ChunkProviderServer.java:225)
at abw.a(Chunk.java:1107)
at iy.c(ChunkProviderServer.java:129)
at iy.d(ChunkProviderServer.java:142)
at aab.e(World.java:402)
at aab.a(World.java:280)
at FCTileEntityMobSpawner.h(FCTileEntityMobSpawner.java:33)
at aab.h(World.java:1755)
at iz.h(WorldServer.java:480)
at net.minecraft.server.MinecraftServer.r(SourceFile:462)
at hz.r(SourceFile:256)
at net.minecraft.server.MinecraftServer.q(SourceFile:397)
at net.minecraft.server.MinecraftServer.run(SourceFile:331)
at gp.run(SourceFile:573)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
at apy.a(SourceFile:178)
at apy.j(SourceFile:158)
at apy.w_(SourceFile:278)
at aab.a(World.java:2430)
at abw.e(Chunk.java:864)
at abw.a(Chunk.java:635)
at aab.f(World.java:432)
at adu.a(WorldGenDungeons.java:115)
at acy.a(ChunkProviderGenerate.java:516)
at iy.a(ChunkProviderServer.java:225)
at abw.a(Chunk.java:1107)
at iy.c(ChunkProviderServer.java:129)
at iy.d(ChunkProviderServer.java:142)
at aab.e(World.java:402)

-- Requested block coordinates --
Details:
Found chunk: true
Location: World: (3295,45,4663), Chunk: (at 15,2,7 in 205,291; contains blocks 3280,0,4656 to 3295,255,4671), Region: (6,9; contains chunks 192,288 to 223,319, blocks 3072,0,4608 to 3583,255,5119)
Stacktrace:
at aab.a(World.java:280)
at FCTileEntityMobSpawner.h(FCTileEntityMobSpawner.java:33)

-- Tile entity being ticked --
Details:
Name: MobSpawner // FCTileEntityMobSpawner
Block type: ID #52 (tile.mobSpawner // FCBlockMobSpawner)
Block data value: 0 / 0x0 / 0b0000
Block location: World: (3297,42,4660), Chunk: (at 1,2,4 in 206,291; contains blocks 3296,0,4656 to 3311,255,4671), Region: (6,9; contains chunks 192,288 to 223,319, blocks 3072,0,4608 to 3583,255,5119)
Actual block type: ID #52 (tile.mobSpawner // FCBlockMobSpawner)
Actual block data value: 0 / 0x0 / 0b0000
Stacktrace:
at aab.h(World.java:1755)
at iz.h(WorldServer.java:480)

-- Affected level --
Details:
Level name: world
All players: 1 total; [jc['jorgebonafe'/75, l='world', x=3091,62, y=75,00, z=4918,56]]
Chunk stats: ServerChunkCache: 1638 Drop: 0
Level seed: 6224087142394433240
Level generator: ID 00 - default, ver 1. Features enabled: true
Level generator options:
Level spawn location: World: (68,64,248), Chunk: (at 4,4,8 in 4,15; contains blocks 64,0,240 to 79,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 2499019 game time, 2499019 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 70382 (now: false), thunder time: 46199 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
at net.minecraft.server.MinecraftServer.r(SourceFile:462)
at hz.r(SourceFile:256)
at net.minecraft.server.MinecraftServer.q(SourceFile:397)
at net.minecraft.server.MinecraftServer.run(SourceFile:331)
at gp.run(SourceFile:573)

-- System Details --
Details:
Minecraft Version: 1.5.2
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_161, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 29913632 bytes (28 MB) / 197132288 bytes (188 MB) up to 954728448 bytes (910 MB)
JVM Flags: 1 total; -Xmx1024M
AABB Pool Size: 8262 (462672 bytes; 0 MB) allocated, 8229 (460824 bytes; 0 MB) used
Suspicious classes: FCBlockPistonExtension, FCBlockPistonMoving, FCBlockJackOLantern, ...]
IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
Profiler Position: N/A (disabled)
Vec3 Pool Size: 1602 (89712 bytes; 0 MB) allocated, 1330 (74480 bytes; 0 MB) used
Player Count: 1 / 10; [jc['jorgebonafe'/75, l='world', x=3091,62, y=75,00, z=4918,56]]
Is Modded: Unknown (can't tell)
Type: Dedicated Server (map_server.txt)

From the report it seems to be related to a mob spawner somehow... I was in a server, the seed is 6224087142394433240,
my location was 3091,75,4918 and I was moving southeast toward some pumpkins.

I cannot reproduce the crash. When I entered the server again it didn't happen anymore. I also tried creating a single player game with the same seed and teleported over there, and nothing went wrong. I don't know if this is a bug or some random chunk glitch or something...

[FlowerChild]

That appears to be me, and an old one likely going back years.

Looks like the mossy cobble generation on the mob spawner was checking blocks within its range, and reached into a chunk that hadn't been generated yet, randomly hit a chest that didn't have a tile entity assigned to it yet for its contents, and went boom.

Will put in the appropriate test to prevent that happening. Thanks for posting this, as it's likely an exceedingly rare bug that would just randomly happen to people from time to time. I don't recall when I first put in mossy cobble gen, but it's likely been in the mod ever since.

[jorgebonafe]

No problem, glad I could help