I was making a hopper mine cart Drop-off Station and the game just crashed several times and deleted me world. The world files has not changed, so i just need to create a world with the same name, and it will be there.

What I expected to happen was...:
The game should not crash

What actually happened was...:
I was building a Hopper mine cart Drop-off Station (2 right next to each other and it just crashed

Steps to Reproduce:
1. I was Building a hopper mine cart Drop-off Station that can be found here :
https://www.youtube.com/watch?v=xq4zsA58Myg
2. drop items on a block on top of it
NOTE: it was 2 right next to each other, on 1 track.

Crash Report:(I Didn't See one so)
---- Minecraft Crash Report ----
// There are four lights!

Time: 11/17/15 5:18 PM
Description: Exception while updating neighbours

java.lang.IllegalArgumentException: Cannot get property arg{name=shape, clazz=class ajh$b, values=[north_south, east_west, ascending_east, ascending_west, ascending_north, ascending_south]} as it does not exist in aqu{block=minecraft:unpowered_comparator, properties=[facing, mode, powered]}
	at aqu$a.c(SourceFile:165)
	at ane.a(SourceFile:115)
	at ane.a(SourceFile:102)
	at ane.b(SourceFile:136)
	at ajh.a(SourceFile:454)
	at ahm.e(SourceFile:447)
	at ahm.a(SourceFile:424)
	at akj.h(SourceFile:209)
	at ant.b(SourceFile:130)
	at arv.a(SourceFile:441)
	at ahm.a(SourceFile:312)
	at akj.b(SourceFile:68)
	at lp.a(SourceFile:646)
	at lp.d(SourceFile:215)
	at net.minecraft.server.MinecraftServer.D(SourceFile:616)
	at net.minecraft.server.MinecraftServer.C(SourceFile:552)
	at bxw.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:456)
	at java.lang.Thread.run(Thread.java:745)


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

-- Head --
Stacktrace:
	at aqu$a.c(SourceFile:165)
	at ane.a(SourceFile:115)
	at ane.a(SourceFile:102)
	at ane.b(SourceFile:136)
	at ajh.a(SourceFile:454)

-- Block being updated --
Details:
	Source block type: ID #94 (tile.diode // ant)
	Block: minecraft:golden_rail[powered=true,shape=east_west]
	Block location: World: (367,5,-3343), Chunk: (at 15,0,1 in 22,-209; contains blocks 352,0,-3344 to 367,255,-3329), Region: (0,-7; contains chunks 0,-224 to 31,-193, blocks 0,0,-3584 to 511,255,-3073)
Stacktrace:
	at ahm.e(SourceFile:447)
	at ahm.a(SourceFile:424)
	at akj.h(SourceFile:209)
	at ant.b(SourceFile:130)
	at arv.a(SourceFile:441)
	at ahm.a(SourceFile:312)
	at akj.b(SourceFile:68)

-- Block being ticked --
Details:
	Block: minecraft:powered_repeater[delay=1,facing=west,locked=false]
	Block location: World: (365,5,-3343), Chunk: (at 13,0,1 in 22,-209; contains blocks 352,0,-3344 to 367,255,-3329), Region: (0,-7; contains chunks 0,-224 to 31,-193, blocks 0,0,-3584 to 511,255,-3073)
Stacktrace:
	at lp.a(SourceFile:646)
	at lp.d(SourceFile:215)

-- Affected level --
Details:
	Level name: asdfdsaf
	All players: 1 total; [lr['Pineappleplayz'/111, l='asdfdsaf', x=370.44, y=6.37, z=-3340.17]]
	Chunk stats: ServerChunkCache: 881 Drop: 0
	Level seed: -8302372831906423387
	Level generator: ID 01 - flat, ver 0. Features enabled: true
	Level generator options: 
	Level spawn location: World: (896,4,-126), Chunk: (at 0,0,2 in 56,-8; contains blocks 896,0,-128 to 911,255,-113), Region: (1,-1; contains chunks 32,-32 to 63,-1, blocks 512,0,-512 to 1023,255,-1)
	Level time: 151157 game time, 227 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 11580 (now: true), thunder time: 12522 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.D(SourceFile:616)
	at net.minecraft.server.MinecraftServer.C(SourceFile:552)
	at bxw.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:456)
	at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
	Minecraft Version: 15w46a
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 4097270024 bytes (3907 MB) / 4268163072 bytes (4070 MB) up to 4268163072 bytes (4070 MB)
	JVM Flags: 7 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx4G -Xms4G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn256M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [lr['Pineappleplayz'/111, l='asdfdsaf', x=370.44, y=6.37, z=-3340.17]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.