---- Minecraft Crash Report ----
// Everything's going to plan. No, really, that was supposed to happen.

Time: 29.7.2015 17:44
Description: Ticking block entity

java.lang.IllegalArgumentException: Cannot get property any{name=shape, clazz=class agf$b, values=[north_south, east_west, ascending_east, ascending_west, ascending_north, ascending_south]} as it does not exist in anm{block=minecraft:rail, properties=[shape]}
	at anm$a.b(SourceFile:132)
	at agf$a.<init>(SourceFile:49)
	at agf$a.b(SourceFile:120)
	at agf$a.d(SourceFile:229)
	at agf$a.a(SourceFile:246)
	at agf.a(SourceFile:468)
	at agf.c(SourceFile:423)
	at aok.a(SourceFile:551)
	at aen.a(SourceFile:291)
	at ang.c(SourceFile:145)
	at aen.j(SourceFile:1312)
	at lg.j(SourceFile:479)
	at net.minecraft.server.MinecraftServer.B(SourceFile:607)
	at net.minecraft.server.MinecraftServer.A(SourceFile:535)
	at bsg.A(SourceFile:152)
	at net.minecraft.server.MinecraftServer.run(SourceFile:451)
	at java.lang.Thread.run(Unknown Source)


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

-- Head --
Stacktrace:
	at anm$a.b(SourceFile:132)
	at agf$a.<init>(SourceFile:49)
	at agf$a.b(SourceFile:120)
	at agf$a.d(SourceFile:229)
	at agf$a.a(SourceFile:246)
	at agf.a(SourceFile:468)
	at agf.c(SourceFile:423)
	at aok.a(SourceFile:551)
	at aen.a(SourceFile:291)
	at ang.c(SourceFile:145)

-- Block entity being ticked --
Details:
	Name: Piston // ang
	Block type: ID #27 (tile.goldenRail // aka)
	Block data value: 0 / 0x0 / 0b0000
	Block location: World: (90,64,220), Chunk: (at 10,4,12 in 5,13; contains blocks 80,0,208 to 95,255,223), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Actual block type: ID #27 (tile.goldenRail // aka)
	Actual block data value: 0 / 0x0 / 0b0000
Stacktrace:
	at aen.j(SourceFile:1312)
	at lg.j(SourceFile:479)

-- Affected level --
Details:
	Level name: glitch
	All players: 1 total; [lh['jktm'/197, l='glitch', x=90,34, y=64,00, z=221,70]]
	Chunk stats: ServerChunkCache: 1227 Drop: 0
	Level seed: -8120029475494256351
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: 92,00,64,00,256,00 - World: (92,64,256), Chunk: (at 12,4,0 in 5,16; contains blocks 80,0,256 to 95,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 109738 game time, 70855 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 8706 (now: false), thunder time: 1110 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.B(SourceFile:607)
	at net.minecraft.server.MinecraftServer.A(SourceFile:535)
	at bsg.A(SourceFile:152)
	at net.minecraft.server.MinecraftServer.run(SourceFile:451)
	at java.lang.Thread.run(Unknown Source)

-- System Details --
Details:
	Minecraft Version: 15w31a
	Operating System: Windows 8.1 (amd64) version 6.3
	Java Version: 1.8.0_40, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 1161113088 bytes (1107 MB) / 1611137024 bytes (1536 MB) up to 2863661056 bytes (2731 MB)
	JVM Flags: 3 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx3072m -Xms1536m
	IntCache: cache: 1, tcache: 1, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [lh['jktm'/197, l='glitch', x=90,34, y=64,00, z=221,70]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.