Server error 16w39a

Minecraft Crash Report ----
// Uh... Did I do that?

Time: 28.09.2016 18:44
Description: Ticking block entity

java.lang.NullPointerException: Ticking block entity
at asg.b(SourceFile:316)
at asg.c(SourceFile:372)
at asg.b(SourceFile:401)
at asi.a(SourceFile:345)
at asi.a(SourceFile:364)
at asi.a(SourceFile:332)
at asi.J(SourceFile:193)
at asi.o(SourceFile:135)
at asi.F_(SourceFile:122)
at ajl.k(SourceFile:1429)
at lv.k(SourceFile:549)
at net.minecraft.server.MinecraftServer.D(SourceFile:634)
at lg.D(SourceFile:335)
at net.minecraft.server.MinecraftServer.C(SourceFile:562)
at net.minecraft.server.MinecraftServer.run(SourceFile:466)
at java.lang.Thread.run(Unknown Source)

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

– Head –
Thread: Server thread
Stacktrace:
at asg.b(SourceFile:316)
at asg.c(SourceFile:372)
at asg.b(SourceFile:401)
at asi.a(SourceFile:345)
at asi.a(SourceFile:364)
at asi.a(SourceFile:332)
at asi.J(SourceFile:193)
at asi.o(SourceFile:135)
at asi.F_(SourceFile:122)

– Block entity being ticked –
Details:
Name: minecraft:hopper // asi
Block type: ID #154 (tile.hopper // aoa)
Block data value: 5 / 0x5 / 0b0101
Block location: World: (-1545,45,1525), Chunk: (at 7,2,5 in -97,95; contains blocks -1552,0,1520 to -1537,255,1535), Region: (-4,2; contains chunks -128,64 to -97,95, blocks -2048,0,1024 to -1537,255,1535)
Actual block type: ID #154 (tile.hopper // aoa)
Actual block data value: 5 / 0x5 / 0b0101
Stacktrace:
at ajl.k(SourceFile:1429)
at lv.k(SourceFile:549)

– Affected level –
Details:
Level name: world
All players: 1 total; [lx['CosminPlaysMC'/22, l='world', x=-1566,00, y=80,00, z=1465,00]]
Chunk stats: ServerChunkCache: 425 Drop: 0
Level seed: -3558144527798569323
Level generator: ID 04 - customized, ver 0. Features enabled: true
Level generator options: {"coordinateScale":684.412,"heightScale":684.412,"lowerLimitScale":512.0,"upperLimitScale":512.0,"depthNoiseScaleX":200.0,"depthNoiseScaleZ":200.0,"depthNoiseScaleExponent":0.5,"mainNoiseScaleX":80.0,"mainNoiseScaleY":160.0,"mainNoiseScaleZ":80.0,"baseSize":8.5,"stretchY":12.0,"biomeDepthWeight":1.0,"biomeDepthOffset":0.0,"biomeScaleWeight":1.0,"biomeScaleOffset":0.0,"seaLevel":63,"useCaves":true,"useDungeons":true,"dungeonChance":35,"useStrongholds":true,"useVillages":true,"useMineShafts":true,"useTemples":true,"useMonuments":true,"useRavines":true,"useWaterLakes":true,"waterLakeChance":4,"useLavaLakes":true,"lavaLakeChance":80,"useLavaOceans":false,"fixedBiome":-1,"biomeSize":4,"riverSize":4,"dirtSize":33,"dirtCount":10,"dirtMinHeight":0,"dirtMaxHeight":256,"gravelSize":33,"gravelCount":8,"gravelMinHeight":0,"gravelMaxHeight":256,"graniteSize":33,"graniteCount":10,"graniteMinHeight":0,"graniteMaxHeight":80,"dioriteSize":33,"dioriteCount":10,"dioriteMinHeight":0,"dioriteMaxHeight":80,"andesiteSize":33,"andesiteCount":10,"andesiteMinHeight":0,"andesiteMaxHeight":80,"coalSize":17,"coalCount":20,"coalMinHeight":0,"coalMaxHeight":128,"ironSize":9,"ironCount":20,"ironMinHeight":0,"ironMaxHeight":64,"goldSize":9,"goldCount":2,"goldMinHeight":0,"goldMaxHeight":32,"redstoneSize":8,"redstoneCount":8,"redstoneMinHeight":0,"redstoneMaxHeight":16,"diamondSize":8,"diamondCount":1,"diamondMinHeight":0,"diamondMaxHeight":16,"lapisSize":7,"lapisCount":1,"lapisCenterHeight":16,"lapisSpread":16}
Level spawn location: World: (-1134,70,2185), Chunk: (at 2,4,9 in -71,136; contains blocks -1136,0,2176 to -1121,255,2191), Region: (-3,4; contains chunks -96,128 to -65,159, blocks -1536,0,2048 to -1025,255,2559)
Level time: 3392607 game time, 4493507 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 94932 (now: false), thunder time: 28099 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: true
Stacktrace:
at net.minecraft.server.MinecraftServer.D(SourceFile:634)
at lg.D(SourceFile:335)
at net.minecraft.server.MinecraftServer.C(SourceFile:562)
at net.minecraft.server.MinecraftServer.run(SourceFile:466)
at java.lang.Thread.run(Unknown Source)

– System Details –
Details:
Minecraft Version: 16w39a
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.8.0_101, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 877188904 bytes (836 MB) / 1029177344 bytes (981 MB) up to 1029177344 bytes (981 MB)
JVM Flags: 2 total; -Xms1024M -Xmx1024M
IntCache: cache: 3, tcache: 0, allocated: 13, tallocated: 95
Profiler Position: N/A (disabled)
Player Count: 1 / 3; [lx['CosminPlaysMC'/22, l='world', x=-1566,00, y=80,00, z=1465,00]]
Is Modded: Unknown (can't tell)
Type: Dedicated Server (map_server.txt)