Hopper: java.lang.NullPointerException: Ticking block entity

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-2921640/

Crash:

java.lang.NullPointerException: Ticking block entity
	at aro.d(SourceFile:526)
	at aro.c(SourceFile:436)
	at aro.a(SourceFile:391)
	at aro.H(SourceFile:247)
	at aro.m(SourceFile:194)
	at aro.D_(SourceFile:181)
	at aiu.k(SourceFile:1422)
	at lu.k(SourceFile:549)
	at net.minecraft.server.MinecraftServer.D(SourceFile:627)
	at net.minecraft.server.MinecraftServer.C(SourceFile:555)
	at caj.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:459)
	at java.lang.Thread.run(Thread.java:745)

The following is the first clean report made public about this crash:

---- Minecraft Crash Report ----
// Oops.

Time: 8/11/16 7:09 PM
Description: Ticking block entity

java.lang.NullPointerException: Ticking block entity
	at aro.d(SourceFile:526)
	at aro.c(SourceFile:436)
	at aro.a(SourceFile:391)
	at aro.H(SourceFile:247)
	at aro.m(SourceFile:194)
	at aro.D_(SourceFile:181)
	at aiu.k(SourceFile:1422)
	at lu.k(SourceFile:549)
	at net.minecraft.server.MinecraftServer.D(SourceFile:627)
	at net.minecraft.server.MinecraftServer.C(SourceFile:555)
	at caj.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:459)
	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 --
Thread: Server thread
Stacktrace:
	at aro.d(SourceFile:526)
	at aro.c(SourceFile:436)
	at aro.a(SourceFile:391)
	at aro.H(SourceFile:247)
	at aro.m(SourceFile:194)
	at aro.D_(SourceFile:181)

-- Block entity being ticked --
Details:
	Name: minecraft:hopper // aro
	Block type: ID #154 (tile.hopper // anj)
	Block data value: 3 / 0x3 / 0b0011
	Block location: World: (-319,31,280), Chunk: (at 1,1,8 in -20,17; contains blocks -320,0,272 to -305,255,287), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Actual block type: ID #154 (tile.hopper // anj)
	Actual block data value: 3 / 0x3 / 0b0011
Stacktrace:
	at aiu.k(SourceFile:1422)
	at lu.k(SourceFile:549)

-- Affected level --
Details:
	Level name: Etho's LP
	All players: 1 total; [lw['mutantmerle76'/246, l='Etho's LP', x=-320.98, y=31.50, z=280.69]]
	Chunk stats: ServerChunkCache: 1091 Drop: 0
	Level seed: -3561483247160496430
	Level generator: ID 03 - amplified, ver 0. Features enabled: true
	Level generator options: 
	Level spawn location: World: (-235,64,142), Chunk: (at 5,4,14 in -15,8; contains blocks -240,0,128 to -225,255,143), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 149018660 game time, 170796507 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 155110 (now: false), thunder time: 115629 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.MinecraftServer.D(SourceFile:627)
	at net.minecraft.server.MinecraftServer.C(SourceFile:555)
	at caj.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:459)
	at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
	Minecraft Version: 16w32b
	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: 374276032 bytes (356 MB) / 887169024 bytes (846 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -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; [lw['mutantmerle76'/246, l='Etho's LP', x=-320.98, y=31.50, z=280.69]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-2921640/77046580/