Crash: java.lang.IllegalArgumentException: Cannot get property ... as it does not exist in aqu{block=minecraft:unpowered_comparator, properties=[facing, mode, powered]}

Same problem here.

I have an automatic wheat farm with a couple standard hopper minecart unloading stations.

"Thanks" to bug 88668 ( https://bugs.mojang.com/browse/MC-88668 ) my hopper minecarts are actually empty, but any time I enable them to pick up items or directly put items inside the game crashes as soon as one of them reach the unloading station.

My error is almost identical (except it says "repeater" instead of "comparator").

Minecraft Crash Report ----
// Would you like a cupcake?

Time: 14/11/15 17.04
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:436)
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=north_south]
Block location: World: (473,89,-549), Chunk: (at 9,5,11 in 29,-35; contains blocks 464,0,-560 to 479,255,-545), Region: (0,-2; contains chunks 0,-64 to 31,-33, blocks 0,0,-1024 to 511,255,-513)
Stacktrace:
at ahm.e(SourceFile:447)
at ahm.a(SourceFile:436)
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=north,locked=false]
Block location: World: (473,89,-551), Chunk: (at 9,5,9 in 29,-35; contains blocks 464,0,-560 to 479,255,-545), Region: (0,-2; contains chunks 0,-64 to 31,-33, blocks 0,0,-1024 to 511,255,-513)
Stacktrace:
at lp.a(SourceFile:646)
at lp.d(SourceFile:215)

– Affected level –
Details:
Level name: Let's play
All players: 1 total; [lr['MandelCube'/112, l='Let's play', x=533,35, y=47,00, z=-417,30]]
Chunk stats: ServerChunkCache: 960 Drop: 0
Level seed: 2470347526754821213
Level generator: ID 00 - default, ver 1. Features enabled: true
Level generator options:
Level spawn location: World: (200,64,240), Chunk: (at 8,4,0 in 12,15; contains blocks 192,0,240 to 207,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 10966632 game time, 14509670 day time
Level dimension: 1
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 25734 (now: false), thunder time: 27095 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
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 7 (amd64) version 6.1
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot™ 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 251321552 bytes (239 MB) / 473972736 bytes (452 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.h​eapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [lr['MandelCube'/112, l='Let's play', x=533,35, y=47,00, z=-417,30]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

I have the same problem, and here is the game output before it crashes:

[07:15:09] [Client thread/INFO]: LWJGL Version: 2.9.4
[07:15:10] [Client thread/INFO]: Reloading ResourceManager: Default
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:block.brewing_stand.brew
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:block.chorus_flower.death
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:block.chorus_flower.grow
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:enchant.thorns.hit
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.guardian.thorns
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.horse.eat
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.player.attack.crit
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.player.attack.knockback
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.player.attack.parry
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.player.attack.strong
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.player.attack.sweep
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.player.attack.weak
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.rabbit.attack
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.shield.block
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.shulker.ambient
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.shulker.close
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.shulker.death
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.shulker.open
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.shulker_bullet.hurt
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.witch.ambient
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.witch.death
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.witch.drink
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.witch.hurt
[07:15:17] [Client thread/WARN]: Missing sound for event: minecraft:entity.witch.throw
[07:15:17] [Sound Library Loader/INFO]: Starting up SoundSystem...
[07:15:17] [Thread-5/INFO]: Initializing LWJGL OpenAL
[07:15:17] [Thread-5/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
[07:15:18] [Thread-5/INFO]: OpenAL initialized.
[07:15:18] [Sound Library Loader/INFO]: Sound engine started
[07:15:18] [Client thread/INFO]: Created: 1024x512 textures-atlas
[07:15:20] [Client thread/ERROR]: Realms module missing
[07:15:23] [Server thread/INFO]: Starting integrated minecraft server version 15w46a
[07:15:23] [Server thread/INFO]: Generating keypair
[07:15:24] [Server thread/INFO]: Preparing start region for level 0
[07:15:25] [Server thread/INFO]: Preparing spawn area: 28%
[07:15:26] [Server thread/INFO]: Changing view distance to 12, from 10
[07:15:26] [Server thread/INFO]: Pineappleplayz[local:E:f6d532c2] logged in with entity id 298 at (282.319421878688, 63.0, 371.30000001192093)
[07:15:26] [Server thread/INFO]: Pineappleplayz joined the game
[07:15:27] [Server thread/INFO]: Saving and pausing game...
[07:15:27] [Server thread/INFO]: Saving chunks for level '1,9 New'/Overworld
[07:15:27] [Server thread/INFO]: Saving chunks for level '1,9 New'/Nether
[07:15:27] [Server thread/INFO]: Saving chunks for level '1,9 New'/The End
[07:15:29] [Server thread/ERROR]: Encountered an unexpected exception
e: Exception while updating neighbours
at net.minecraft.server.MinecraftServer.D(SourceFile:620) ~[15w46a.jar:?]
at net.minecraft.server.MinecraftServer.C(SourceFile:552) ~[15w46a.jar:?]
at bxw.C(SourceFile:154) ~[15w46a.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:456) [15w46a.jar:?]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_25]
Caused by: 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) ~[15w46a.jar:?]
at ane.a(SourceFile:115) ~[15w46a.jar:?]
at ane.a(SourceFile:102) ~[15w46a.jar:?]
at ane.b(SourceFile:136) ~[15w46a.jar:?]
at ajh.a(SourceFile:454) ~[15w46a.jar:?]
at ahm.e(SourceFile:447) ~[15w46a.jar:?]
at ahm.a(SourceFile:424) ~[15w46a.jar:?]
at akj.h(SourceFile:209) ~[15w46a.jar:?]
at ant.b(SourceFile:130) ~[15w46a.jar:?]
at arv.a(SourceFile:441) ~[15w46a.jar:?]
at ahm.a(SourceFile:312) ~[15w46a.jar:?]
at akj.b(SourceFile:68) ~[15w46a.jar:?]
at lp.a(SourceFile:646) ~[15w46a.jar:?]
at lp.d(SourceFile:215) ~[15w46a.jar:?]
at net.minecraft.server.MinecraftServer.D(SourceFile:616) ~[15w46a.jar:?]
... 4 more

Has been fixed for me in 15w47c

No reports since 15w46a, assuming fixed.