Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here

What actually happened was...:
---- Minecraft Crash Report ----
// Ouch. That hurt

Time: 12/3/16 10:27 AM
Description: Ticking block entity

java.lang.IllegalArgumentException: Cannot get property atw

{name=facing, clazz=class cv, values=[down, up, north, south, west, east]}

as it does not exist in atk

{block=minecraft:air, properties=[]}

at atk$a.c(SourceFile:166)
at atd.j(SourceFile:119)
at atd.f(SourceFile:130)
at atd.F_(SourceFile:308)
at ajq.k(SourceFile:1484)
at beq.t(SourceFile:1649)
at beq.av(SourceFile:967)
at beq.a(SourceFile:395)
at net.minecraft.client.main.Main.main(SourceFile:124)

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

– Head –
Thread: Client thread
Stacktrace:
at atk$a.c(SourceFile:166)
at atd.j(SourceFile:119)
at atd.f(SourceFile:130)
at atd.F_(SourceFile:308)

– Block entity being ticked –
Details:
Name: minecraft:piston // atd
Block type: ID #33 (tile.pistonBase // ata)
Block data value: 0 / 0x0 / 0b0000
Block location: World: (4184,124,-46202), Chunk: (at 8,7,6 in 261,-2888; contains blocks 4176,0,-46208 to 4191,255,-46193), Region: (8,-91; contains chunks 256,-2912 to 287,-2881, blocks 4096,0,-46592 to 4607,255,-46081)
Actual block type: ID #33 (tile.pistonBase // ata)
Actual block data value: 2 / 0x2 / 0b0010
Stacktrace:
at ajq.k(SourceFile:1484)

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [bpq['Powerhungryadmin'/5061, l='MpServer', x=4182.70, y=118.00, z=-46201.88]]
Chunk stats: MultiplayerChunkCache: 49, 49
Level seed: 0
Level generator: ID 01 - flat, ver 0. Features enabled: false
Level generator options:
Level spawn location: World: (0,0,0), Chunk: (at 0,0,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 139358547 game time, 139384206 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 1 total; [bpq['Powerhungryadmin'/5061, l='MpServer', x=4182.70, y=118.00, z=-46201.88]]
Retry entities: 0 total; []
Server brand: PaperSpigot
Server type: Non-integrated multiplayer server
Stacktrace:
at bno.a(SourceFile:365)
at beq.b(SourceFile:2536)
at beq.a(SourceFile:404)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.11
Operating System: Windows 10 (x86) version 10.0
Java Version: 1.8.0_111, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 101233256 bytes (96 MB) / 254337024 bytes (242 MB) up to 523501568 bytes (499 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.11
LWJGL: 2.9.4
OpenGL: Intel(R) HD Graphics 520 GL version 4.4.0 - Build 20.19.15.4390, Intel
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: Yes
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs:
Current Language: English (US)
Profiler Position: N/A (disabled)
CPU: 4x Intel(R) Core(TM) i3-6100U CPU @ 2.30GHz

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...