[MC-68149] 6 Sided Piston Dedicated Server crash

Upon using the command "/setblock ~ ~ ~ piston 6" or "/setblock ~ ~ ~ sticky_piston 6" The client disconnects as the server, and only the server, crashes.

What I expected to happen:
Cool 6 faced piston (crate)
What happened:
Server not client crash
Reproduce above

Client Log:

[18:47:14] [Client thread/INFO]: [CHAT] An unknown error occurred while attempting to perform this command
[18:47:14] [Client thread/INFO]: [CHAT] [Server] Server is restarting. World is being saved.
[18:47:14] [Client thread/INFO]: [CHAT] [Server: Saved the world]
[18:47:14] [Client thread/INFO]: [CHAT] [Server: Stopping the server]
[18:47:14] [Client thread/INFO]: Reloading ResourceManager: Default
[18:47:14] [Client thread/INFO]: SoundSystem shutting down...
[18:47:14] [Client thread/WARN]: Author: Paul Lamb, www.paulscode.com
[18:47:14] [Sound Library Loader/INFO]: Starting up SoundSystem...
[18:47:14] [Client thread/WARN]: File minecraft:sounds/mob/ghast/fireball.ogg does not exist, cannot add it to event minecraft:item.fireCharge.use
[18:47:15] [Thread-16/INFO]: Initializing LWJGL OpenAL
[18:47:15] [Thread-16/INFO]: (The LWJGL binding of OpenAL.  For more information, see http://www.lwjgl.org)
[18:47:15] [Thread-16/INFO]: OpenAL initialized.
[18:47:15] [Sound Library Loader/INFO]: Sound engine started
[18:47:15] [Client thread/INFO]: Created: 512x512 textures-atlas

Server Crash (No crash report is saved to disk, copied from log):

[18:47:14] [Server thread/ERROR]: Couldn't process command: 'setblock ~ ~ ~ piston 6'
java.lang.IllegalArgumentException: Cannot set property bes{name=facing, clazz=class el, values=[down, up, north, south, west, east]} to null on block minecraft:piston, it is not an allowed value
	at bed.a(SourceFile:124) ~[minecraft_server.jar:?]
	at bdn.a(SourceFile:409) ~[minecraft_server.jar:?]
	at cm.a(SourceFile:92) ~[minecraft_server.jar:?]
	at ab.a(SourceFile:80) [minecraft_server.jar:?]
	at ab.a(SourceFile:63) [minecraft_server.jar:?]
	at rj.d(SourceFile:635) [minecraft_server.jar:?]
	at rj.a(SourceFile:622) [minecraft_server.jar:?]
	at lu.a(SourceFile:37) [minecraft_server.jar:?]
	at lu.a(SourceFile:9) [minecraft_server.jar:?]
	at ih.run(SourceFile:13) [minecraft_server.jar:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.7.0_51]
	at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.7.0_51]
	at net.minecraft.server.MinecraftServer.z(SourceFile:576) [minecraft_server.jar:?]
	at po.z(SourceFile:305) [minecraft_server.jar:?]
	at net.minecraft.server.MinecraftServer.y(SourceFile:531) [minecraft_server.jar:?]
	at net.minecraft.server.MinecraftServer.run(SourceFile:447) [minecraft_server.jar:?]
	at java.lang.Thread.run(Unknown Source) [?:1.7.0_51]
[18:47:14] [Server thread/INFO]: [Server] Server is restarting. World is being saved.
[18:47:14] [Server thread/INFO]: Saving is already turned on.
[18:47:14] [Server thread/INFO]: Saving...
[18:47:14] [Server thread/INFO]: Saved the world
[18:47:14] [Server thread/INFO]: Stopping the server
[18:47:14] [Server thread/INFO]: Stopping server
[18:47:14] [Server thread/INFO]: Saving players
[18:47:14] [Server thread/INFO]: Saving worlds
[18:47:14] [Server thread/INFO]: Saving chunks for level 'world'/Overworld
[18:47:14] [Server thread/INFO]: Saving chunks for level 'world'/Nether
[18:47:14] [Server thread/INFO]: Saving chunks for level 'world'/The End
[18:47:14] [Server Shutdown Thread/INFO]: Stopping server
[18:47:14] [Server Shutdown Thread/INFO]: Saving players

After this point the server is stuck in a "limbo" state, not fully stopped, but rejecting players with: "java.net.ConnectExecption: Connection refused: no further information:" and I don't want to force close it, in fear of losing the world